Most of the decisions we make in the field are open to our judgment and interpretation of the regs, on site situations and manufacturers instructions. I would much prefer someone like Mr Hunt to contact you privately to discuss a query rather than points score and make you out to be wrong in public. Your videos are spot on for us all to reference and make decisions on the day so keep them coming especially for the new entrants. Some people are visual learners and they take a lot more in from these videos than a book and gives them the confidence to get through the ACS. 👍
Derek, we work in an industry that is open to interpretation, personally combi gas rating I usually rate hot water as the max, as you say potentially it can help highlight faults, like blocked plates, not all boilers on max setting show the full hot water input, due to range rating etc. I do the max whilst doing the FGA but usually do a final as left gas rate, in hot water for combi boilers, standard heat only put both on and do a final then. Keep doing what you are doing, we are all gas safe registered, and at the end of the day, unless like you say you are a trainee, we all have our own understanding of things and over the years build a sound engineering judgement, providing we have followed updates and used everyday as a school day and learnt through our journey. I was a trainer for many years at British Gas, our guidance was printed in the old operational procedures, so most of the time was pretty sound. In wider industry it’s different the written word isn’t there for every task you come across, there are different guides with varying interpretations, so at the end of the day all we can do is talk to each other, keep up to date with changes, and get through doing what we think is best practice. Keep up the good work, and stick to what you think is correct, like most trainers if there is anything you doubt I’m sure you will dig deeper for conformation just to clarify you are passing on the correct information to your groups of learners 👍
I am a trainer too and I agree with you. The 5 and 10% I use with students because you will never get an exact figure to match the MI’s, therefore, an inexperienced engineer will likely think there is a problem with the appliance. We have to remember that when boilers are tested they use a rig giving consistent CV’s and installation parameters so all boilers are tested the same. I used to do gas audits as well and if I saw a gas rate or heat input exactly the same reading as the MI’s on their gas safety certificate I knew they probably had not even carried out the test. Obviously you can’t prove it but it does give you a concern regarding the individual. Thanks for sharing the video.
Got to say I’ve been taught to gas rate in high and low and……. After watching this I realise what your saying is far more beneficial and gives me way more information about what the appliance is actually doing 👍🏼.
Brilliant video Derek, I have always done a 10 minuet warm up the CH test the rate on MAX next HW flow is OK then on MAX rate, works for me for 50 years.
Not long passed my tests to become gas engineer found your videos very helpful can’t comment against people having a go as they probs no more than me but I’ve found your videos very helpful as have a lot of others keep up the good work
Hello! As always great vid! I was always under the impression that rating in HW & CH have you the rate in a more really life situation? How the customer will actually use the appliance! They won’t ever put it in engineer mode! So I agree with you!! 👍👍
I always understood it that on Commissioning you follow the Manufacturers Manual and fully complete the benchmark where applicable (Gas rate (min and max to me, means service mode, (as most manuals show this) which will put the unit in to min and max mode directly)), Combi cold water temp, dhw temp and the flow rate stated for that appliance, as well as all the other information required, For servicing ALL manufacturers manuals have a section on the recommended way to service their appliance (and what to further carry out if it fails the fan depression test), and like you say, LPG do not always have meters, so the co/co2, ppm, fgt, efficiency and ratio will tell you a lot. Maybe you should just put a banner up at the start of some videos with a disclaimer mainly for the one who commented then removed the comments (did he realise he was an a**h*le). Keep the vids coming, :) very good video :):):):) deffo thumbs up from me.
I'm with you 100%! When I do gas rating and flue analysis, I write down the various test results, at the meter ,boiler and taps. I feel that I'm more likely to spot any issues this way because all of the figures are in my face and as they are all interrelated, any anomalies will leap off the page,rather than saving logs and printing separately, if that makes sense! Anyway, understanding what you're looking at is the key!
As a newly qualified gas engineer I must admit I have always been a bit confused about this, It seems I was not alone! I can see why gas rating at max rate would remove the unpredicatability of the boilers modulating effect on gas consumption but the point is we want to see how the boiler is actually performing. I have found that in some installations putting the boiler on max rate causes it to overheat and cut out before you can gas rate. Likewise in properties with low cold water supply flow rates the boiler moldates down to maintain a consant hot water temperature, the same can occur on hot days with the central heating. So what is right, to be frank I am still unsure. At least if you put the boiler into max rate for the combustion analysis and do a gas rate at the same time its consistant and you can compare the gas rate with the CPA results. Please dont shoot me down in flames I genuinely want to be better informed.
When analysing I run the boiler for between 15 and 30 minutes before i take the readings so I gas rate first not at the same time so I get the correct readings.
@@Silenced2024 baxi vokera viewsmann I tried it on a British Gas Worcester 542 fucker wouldn’t work kept locking out and over heating shoved fga in quick time had keep turing it gas off and running hot tap cool plate and heat ex down hate worcesters with a passion cut myself 3 times changing left block
I normally gas rate in test modes (where available), but I'm doubting my life choices. I can see both sides of the argument and seeing how a boiler performs in situ makes a lot of sense. 🤪
You are offering a great service. It is interesting that there are different options on many areas. I appreciate you taking the time to review it; you are right.
A plumber's perspective here... If I talk about what I understand better (to keep it simple and avoid talking about things I don't understand properly), I'll focus on an old non-modulating boiler that is designed not to condense. If I find a customer's heat-only or system boiler is gas-rated so low it won't reach the set flow temperature with all TRVs on max, I might suggest it's probably under-rated and needs a RGI to increase the gas-rate. However, if it only struggles to get to that temperature when the DHW cylinder is also calling for heat, then it might depend on how often that is likely to be the case. If the DHW cylinder is only being heated once a day, it may be worth considering whether it is really an issue, provided the flow is sufficiently hot to get the cylinder to temperature (so, no less than 70°C, say). It is also worth considering that it is unlikely that the TRVs will usually be set to max in normal use. Normal use may result in the actual heat demand from the boiler being considerably lower than the full output of all rads at DT 55 plus cylinder coil on a cold cylinder (most people with zombie boilers rarely run them at 82°C anyway). So, in a way, if the zombie-boiler gas rate is set too low to allow a flow temperature of 82° with a cold cylinder and TRVs set to max, but high enough to heat the cylinder and avoid condensation on the heat exchanger (say 70°), it may well be a perfectly sufficient gas rate (especially if the radiators are oversized), and possibly better than having the boiler cycling in 95% of real-world conditions. In these circumstances, I'm not sure I would bother suggesting the customer get a RGI to increase the gas-rate. So, in my circumstances, I'm looking at what the boiler is doing and is likely to be doing. I.e. taking a practical approach rather than slavish observance to somewhat pharisaical rules. Particularly if those rules are not enshrined in law. So although we are talking about slightly different things, I think we agree on the general approach, which is that the boiler should be set up so it is running in favourable conditions for the majority of the heating season, and not under hypothetical cirumstances that may only exist under arbritrary test conditions.
With the new buildings going up every where in my region of the uk we are finding that the local water authority have reduced the water flow entering properties as well as the original installation engineers are fitting flow regulating valves and pressure reducing valves and then finding they are fitting 35 kw boilers in 2 bedroom properties/flats in these instances checking gas rates become a mine field and a lot more working out is required. You cannot achieve the the correct kw nett reading within the tolerances stated. The equation for doing it traditionally would need to be adapted based on the specific flow rate at the property.
Hello. Would you use net cv rather than gross cv for gas rating if its a condensing boiler? But if not use gross? Also, in table 2 for CH gas rate. What is the relationship between the top row of numbers and the ones underneath? Is the top row(26,32,40) showing three different size ideal boilers and how much kw they use on high central heating setting? With the row beneath (18.1,26.1,32.1) showing you how much lower than the optimal rate of gas is allowed?
Only thing im in two minds about is.. depending on the system and when the boiler was last in use you will get different gas rates all the time on CH with a modulating GV. So I always thought the point of doing max gas rate was to indicate if the boiler could burn more than it should be possible to, indicating it could potentially do it in normal operation and cause a fault/damage. Min gas rate usually locks out if not set correctly and/or will show on the FGA that its not to MI's but again i thought the min setting gas rate shows that the boiler can operate correctly in its lowest state. That's why it made sense to me to test in min and max on a service visit cause parts can wear out as you said. But im no trainer so this was interesting video and very thought provoking in a good way. Keep these videos coming 👍🏽
I set the boiler to min, then take FGA. Then I set it to max, take the FGA, then do the gas rate at the same time. However in the summer I’ve had days where I can’t keep the boiler running long enough, even trying to GR with the room stat at max. In those cases I will use a tap and GR to that rate instead. It’s a case of using my judgement.
I have this same problem, i always would do Minimum 1st, than max, otherwise it takes ages for the readings to settle down. Did this in front of a Gas Safe Inspector, and his reply was to to my manager was Do you guys ever read the manuals? So i have always done max 1st then min. but on small systems, i always run the hot tap for 10 mins, to allow for the boiler to warm up 1st
Most condensing boilers say gas rate in max mode. This makes sense as it’s a set test. How can you gas rate a boiler that’s modulating and get a reading worthwhile. How ether in the benchmark you could do it in heating and hot water as that’s what it says and it’s just a commissioning test. On Worcester 8000 for example on commissions can have
The only problem with not putting the boiler in service mode when gas rating is , if you have poor flow rate at the taps the boiler will modulate to quickly and will under perform on the gas rate . You need a good water flow rate to get the hot water performance.
I gas rate on max always have done just to check it’s giving me the right kw for the boiler I also do it when I range rate a boiler aswell as fga results
I've had lots of conversations about this subject and have never heard the same conclusions drawn. Essentially, as far as I can see, the gas rate when combined with burner pressure in an old fashioned machine is primarily checking for either a blocked or worn jet. In a modern boiler, assuming no intake or combustion gas flow obstruction or anything that causes downward modulation, this same check will confirm the correct operation of the gas valve, so, surely, checking at any know datum point, max central heating, max dhw, or any stable and known load will give a result that can be used to make this assessment.
I do gas rate in Max to look at performance and compare to MI’s. Most manufacturers ask for that. I then gas rate in hot water and CH to see what’s actually going on. The CH gas rate can be useful for range rating modern appliances
Absolute madness that we’re all questioning gas rating… 💥💥💥 I hope there ain’t no customers who have just had a boiler fitted reading this 😂😂😂 Love ya vids Derek & yours Allen 👍🏻👍🏻
Good video Derek, When I’m commissioning boiler I follow the benchmark an gas rate in Hotwater mode, usually open 2 taps to get maximum flow.. But when I was in training centre I was taught gas rating appliances under maximum load, but theirs was more for gas cookers, fires and older type of boilers what didn’t modulate… I hate trying to Gat rate boilers on maximum with a small heating circuit as it shuts down an reaches temp to quick
If an appliance has max/min service mode, i only gas rate on max on a service, as your putting boiler flat out, so in theory its worst case scenario. If its out, more so below the 10 percent, then its showing me that theres a problem with the boiler like a blocked burner for example. On some CP12s out there, it gives you the option to record for both max and min, but again thats for fga. If its a baxi 105e for example it tells you to run hot tap for fga and thats when i would do my 26.9 checks on hw. Also if you have additional appliances on installation, they also need to be running so that you can determine that the meter can supply the correct amount of gas. If i was installing boilers i would be checking max and min, so i can say that yes, this boiler is correctly installed and working as it should. Your all over it Derek, so keep up the great work your doing.
As a gas boiler user, it worries me that someone is training people that may install my boiler in an incorrect way. You may a clear case for your argument and it seems watertight. I hope my new boiler , last September, was installed by someone trained as you were.
The whole point of gas rate is to see if your getting the manufactured maximum for the appliance and not forgetting if the meter is capable of providing the gas required without a drop of the supply pressure. Try getting your maximum on a hot day without your tap. Nothing wrong with doing both to see if it is performing correctly. The GSR are completely open to interpretation. It's down to the engineer. Each appliance and fit is different follow the MIs. CCN 1 leads on to Commercial change over. They don't have hot water. But you still need to Gas Rate. In the summer the best way to get load is run down your DHW cylinders. So each installation is different. Your the engineer its your gas card. But if you can clearly describe what you have done and why you won't go far wrong. My definition of a boiler is a steel bucket with a flame under its ar5e. You can complicate it as much as you like lol
Cool vid Dman! Company i work for want GR (Gas Rate) in max mode. If no max/min mode then its with hot tap running (DHW) or central heating (CH) depending on boiler & system! 👍
Hi Derek. A big fan of your channel. For me personally, where the MI states that the gas rate should be done in high and low, that's what I prefer to do. But I have a question, if the gas rate is too high or too low (outside of the tolerances), but the combustion analysis is fine, how would you class the boiler? Would you say it's safe?
If a gas rate is too high then it’s ID but too low it’s just poor. As I say in the video why would you gas rate a boiler on high and low that just makes no sense to be because it doesn’t show how the boiler is working. Gas rating the boiler on water and heating will show if you are having problems high and low won’t show problems. Thanks for watching cheers 👍🏻
The success of other cause jealous. This man TomKat, for long, is helping us a lot learning, understanding and be a professional GE on the field with a lot subjects. And he is doing them for free without charging any penny. Instead of the guy asks Tomkat in private and get in conversation and explanation, he came to put this brilliant teacher look like dumb. I am on my way to do my ACS, and apart from my centre training, Tomkat and Viva training academy are my reference and I say Tomkat is my main one. I can refresh, learn and be ready for all subject through this man Tomkat. I will say Tomkat just ignore this thinksmart man and keep doing what you do. I everytime say to my teacher at C.traing that we got a good RUclipsr teacher Tomkat and He says, yes he is a great and good engineers. Thank you for everything you provide for us. May almight bless you.
Have the same problem with working pressure cadent test on hot water we test on maximum had to call them out not getting enough pressure at meter on max they test on hot water and say it’s fine manufacturer says has to be turned off cadent say it’s fine where do you stand then 🤔
Yeh it’s a big pain in the neck. At the end of the day the boiler might never get to its high rate especially if the boiler is massively over sized and the house has poor flow rate this is where our engineers judgement comes in after we have carried out all our tests to see if it’s a boiler fault or installation fault.
I totally agree with you for central heating mode but with a combination boiler you would gas rate at full rate on commissioning and enter that in the hot water section of the bench mark. If servicing a boiler you would check its gas rate on full load during flue gas checks before you you look into boiler setup . Gas rate in range... tick , flue gas analyser correct ratios ...tick, max load and min load ppm...tick, and now you will know if you need to go deeper. the bench mark hot water section clearly states at max load and your tolerances at max load are clearly documented in many manuals as +5 and -10. old bulletins that are no longer in circulation maybe out dated or revised.
If you are gas rating in full load how would you know to go deeper. In my service video I had very low gas rate on hot water so I checked temperature and flow at the tap. The benchmark states max load on hot water and I have never seen the 5 and 10 % in a manual. Maybe I am looking in the wrong place. Like a said in my videos if you can say with confidence that when you check the boiler the way you do it is correct then who can argue with you. Cheers 👍🏻
@@tomkatgastraining thanks for the reply. Bench mark hot water is at full rate you can see that clearly in brackets. tolerances are in all Vaillant and their glow-worm boilers its a standard allowance IMO , if outside of that then you would go deeper ...pipe damage restriction .Inlet pressures etc etc. re the LPG gas rates all manufacturers state 37mb and don't give tolerances probably as a safety line due to bottled supplies but you can weigh gas used and do the math...only joking. we know what the allowable drops are at reg etc so I guess we engineers can use common sense. keep up the great work its great to refresh stuff and discuss
@@geetee50 dose it not mean full rate of the hot water it was written like that before we had condensing boilers should it not have been written differently to make it more clearer.
A guard over condensing flues below 2mtrs is the only rule I think could be updated, I was told what if someone blocked the flue way when I questioned it . That's a bit weak I thought ...stupid rule IMO it should just be a plumb kit must be fitted below 2mtrs.
So to gas rate on heating and hot water would you set the temperature for each at the max on the boiler and then gas rate by turning them on at the programmer individually
Isnt a gas rate to Check if the gas appliance is burning the correct Amount of gas? So if a 24 kw boiler is giving u 18kw you know theres an issue somewhere with the boiler most likely the heat exchanger
Im gonna be totally honest. When I first started, I used to gas rate every condense boiler on high rate, when there were two of us. But as time went on and I started to work alone more I couldn't do it as its a 2 man procedure.So I stopped. Now I work in more commercial properties where you cant just interrupt the gas supply at a whim, still not doing it.
Same. I installed some commercial boilers 4 months ago, they were manufacture commissioned, he didn’t gas rate them. So hard to gas rate in commercial, with kitchens and other appliances on.
I get you completely. You are both right in a way. However if you go of all literature you are more right than Michael. It all depends on the situation you are faced with. Whether you are commisioning a new boiler install or whether you are servicing an old boiler. I must state that peole dont like being told their wrong (human nature maybe) dont take it to heart, Michael just has some growing up to do / improving the way he conducts himself. All the best and thankyou for your uploads as it does keep me on my toes.
Hi Derek, just started service/repair work. I was taught to gas rate on high on low as it's the co2 readings of these readings we need to set/ adjust gas valve. Work exclusively on WB boilers. Their MI's always state service mode for taking readings. I'm confused.
As I say in the video do as you feel fit you are the engineer. As long as you can determine the appliance is safe and working correctly then carry on doing what you do no need to be confused
@@tomkatgastraining Brilliant vid though.. Just goes to show need to adopt a more sophisticated approach and understand what/why you're doing something rather than mechanically going through the motions. I'm going to spend a bit more time going forward and maybe test a bit more and get more readings and have a proper think over them. Keep em coming Derek.. appreciate your efforts!
Should the question be... 'what method did the manufacturer use to obtain their figures.' Shouldn't we be using the same method as the manufacturer used, to be able to make a comparison ..? The manufacturers figures you show us, show a figure for Central heating and hot water mode. Therefore we should be checking in the same way.
can you make a video on gas rating and how what to look for when taking the values? How to interpret the values and if there's a problem what to look for?
@@tomkatgastraining cheers mate, I was looking but most of the gas rate videos cover how to gas rate, unless I am not seeing something. I was hoping to find something where you explained more as to how to interpret a gas rate value when there is nothing wrong and when there is something wrong, if that makes sense?
i went to service a new baxi in a caravan last week.it had 5 rads.when put into high gas rate,it took 3 mins for all rads to be bouncing and i couldnt carry on. the flow rate was so crap at 6 litres it wouldnt modulate fully for long enough.so i used my 35 years of experience to ascertain after a combustion test high /low ( as good as possible) that was safe to leave working..
Genuine question here. What do you do if you gas rate a new appliance and it ends up being too low? Replace appliance under warranty and install at own cost? Maybe manufacturers reinstall new appliance?
There is no mandatory requirement to gas rate but i would always gas rate in high if the boiler allows that, ( depending on the manufacturer's instruction ) Personally i don,t agree with how you did it in your service video and i wouldn’t do it that way. Also, some of the AR and ID you claimed in other videos were also incorrect. Anyone watching any videos on youtube need to check for themselves with the manufacturer of the boilers as things vary with different manufacturers and different models of boiler. No one is correct all the time and sometimes if you phone the manufacturer they can also give you incorrect advice, Keep up the good work.
@@tomkatgastraining Do you ever go on manufacture training days? next time you do let me know and i will come with you. Lets go to Vaillant and we can ask them if your video is how they train out.
@@tomkatgastraining as you know i have experience with both centres and it would be very easy to do videos slagging other people off. Not really good for the new trainees though. I actually thought better of you.
@@AllenHart999 if mr hunt wasn’t so rude with his comments and then remove them I probably wouldn’t have done the video. Yes I do go to manufacturers training days and I have been to Vaillant on numerous times and I know they quote the 5 and 10% even quoting the British standards but again in my video I didn’t say it was law I said what I do like you do in your videos. Please make your video about me being wrong with the ID and AR but don’t remove my comments like you do in your other videos when I make a comment.
@@tomkatgastraining I Would never make a video about you being wrong but you are welcome to call me anytime and I would be happy to tell you. Has any manufacturer ever told you to gas rate and not use service mode? Your service video was unlike anything i have ever been trained and i have been to almost every manufacturer for training. Lets go on a Vaillant day and both film it???
As Derek says, Gas rate is real world test on what the boiler is doing at that point in time,remembering it's in relation to a service, I'll go with Derek 100%, be interesting to see "mikes" vid. (oh hang on !)
When you go on a manufactures training courses they nearly always tell you to use the service mode settings, Otherwise, why would they put them in boilers.
Sometimes people over think this and there certainly is some some confusion and misconception over what is the “ correct “ method of examining the heat input of an appliance Mr Hunt seems to be 100% sure that he is 100% correct and that you are completely wrong but as you have demonstrated there is more than one way of achieving the results you need I personally prefer to measure the heat input on a combi in hot water delivery mode but as long as you can demonstrate that the boiler is delivering the specified outputs then either method is acceptable As you have also pointed out ,sometimes it may not be possible to examine the heat input of an appliance , e.g LPG installation or you could also have a situation where the electronic meter display is faulty and readings cannot be obtained I firmly believe that if you follow what the manufacturer says, work in accordance with the regulations and apply your own professional judgement and common sense to determine if an appliance is operating safely and efficiently then you won’t usually go far wrong
@@jockster5525 Derrick is been very unfair doing this video tbh, in my opinion, it makes him look bitter. We all do videos where we get things a bit wrong, I would always advise to check with the manufacturer, Go on manufacturer training days, What Derrick put in the service video is unlike anything any manufacturers have ever told me, We were not trained that way at British gas either.
@@AllenHart999 hi Allan. Thanks for your input. I could write a long winded reply to this but it'll probably be wrong ☺️ we all have systems and ways of working , I always try to follow the manufacturer scripts and texts , I usually get things right but always open to interpretation and learning from all . Every day is a school day . My tutor is none other than Adrian brown in saffron Walden , a fantastic man who has a great way of teaching and makes it fun and enjoyable. Not sure if you know of Adrian,he was a British gas trainer I think. I'll be running these opinions out to him very soon .
While this is an interesting discussion the importance of this is overstated. Probably 95% of boilers never get gas rated when serviced or when installed for that matter. Engineers just don’t bother.
I feel for you derek, trying to do something beneficial, and time and time again, you get unnecessary abuse. This is pretty simple this, pretty simple indeed. FGA in high and low, to check parameters of the boiler, and for comparison with the MI’s. Gas rating in high and low, and for the benchmark, in high CH also. Because in most circumstances, high is for HW and not CH. As you rightly point out, because it’s modulating, either by itself or by means of load/weather comp, it’s difficult to accurately get right, but it is a useful guide to demonstrating the boiler/controls, parameters of the boiler, are working correctly. Engineer’s judgement indeed, is that so difficult to understand??
Seems a lot of different opinions in the comments……Think this could make a real good informative video, Tomkat, Allen Hart, Gas Safe rep, boiler manufacturer trainers?
A bit of a eye opener, but as usual your thorough explanation goes a long way to convince me that your as usual.... More right then most right wing politicians 😢 Ever thought of a job in politics?
@@tomkatgastraining yes but young uns and newbies i have worked with dont understand that heat input isnt a gas rate. i have asked for the gas rate and they come back with heat input when i needed the cubic meter. Even on commisioning sheet asks for cubic meters.
@@Heatingandplumbing1 you are correct in the benchmark only asks for the ft3 or m3 and I guess it’s poor training if new entrants don’t know the difference.
only one troll in this video, Very sad that Derrick has chosen to show other trainers in videos to try and pull them down, Could of quite easily just blanked the name out.
@Tomkat Gas Training Just to be clear you said the +5% and -10% mean nothing but it is an absolute in Vaillant MIs. Not a guide. And Vaillant only require gas rate on max. All MIs are different and they all have their own quirks. We just need to be on the same side and not slating each other for not knowing everything but be more open minded 😃
I didn’t say it means nothing the 5 and 10 % I said it’s not in any regulations but it is a good guide if you are new into the industry with no engineers judgement.
@@tomkatgastraining Hi Derek, I use your videos for training and support your channel. My point was don't tie ourselves down with any 1 Manufacturer and be aware that they really do have different requirements and use different wording. Again Vaillant insist on Gas rating on Max to get the consumption. As you would say, we know when something is wrong due to our experience. Keep up with videos Derek, you're doing a fine job.
I have trained at both. We could all do videos like Derrick has done today naming people, Its quite sad tbh as i could of done the same with the AR and ID video Derrick did but we need to help the industry and not fight between ourselves
I would not use Ideal boilers as a example, they tend to leave everything open to interpretation, not so long ago they never had a means to force a boiler into full burn rate. There are several manufactures who state that you need to put their boiler into full burn rate and low burn rate for various tests and also tell you what the 10 and 5% figures should be with consideration to other factors. The Bench Mark now requires full burn and low burn Co2 % and Co PPm for which you need to put the appliance into those modes to obtain your figures. I can also show you Bench Mark books that require ratings in heating and hot water. Below I have taken examples, some parts are missing as I don't need a war with the manufacture * ▶ Measure the gas flow rate at _____ gas meter. ▶ Compare the measured values _____ the corresponding values in the table. * H gas in m³/h Nom. +5% −10% 15.3 1.62 1.70 18.4 2.05 1.76 24.7 2.61 2.74 2.35 25.7 2.72 2.86 28.6 3.18 2.73 30.6 3.24 3.40 78 3. 97 3. 40 * The manufacture is telling you how to do the tests in full burn rate and how to use its programmes to fill in the Bench Mark. If the manufacture says these are the values, you are working to this like it or lump it as in court you will have no argument. Your not going to be working any other way when you install this boiler, or when you service it, there training centre will tell you the same, follow these procedures. Using check programmes P.00 Purging programme: P.1 Maximum load check programme: After successful ignition, the Boiler is operated at maximum heat input. P.2 Minimum load check programme: After successful ignition, the Boiler is operated at minimum heat input. * Yes, some wording is changed and some numbers are missing, I don't need a war with the manufacture. My Opinion, Do as the Manufacture says. That book and the Manufacture is God in Court. Maybe you need to fit a new and different boiler every week Derek because they all have slight variances on telling you how to commission and service their boiler. If you cant achieve the KW rating at full burn rate in the mode the manufacture says, within the tolerance allowed, the gas supply is not correct and the appliance is At Risk. You need to go back and look at your video, I think you set a poor example when gas rating your boiler as do other reading through the comments.
You are missing the hole point of the video. Mr hunt said every boiler manufacturers say and every manufacturer must do. But as you say not ever manufacturers are the same my hole point of the video is to follow manufacturers instructions but also understand what figures you are getting and act on what you see. We are supposed to be engineers so let’s be one instead of being sheep
@@tomkatgastraining Just for you as you failed to test the boiler as per manufactures instructions, no where does it say in hot water or heating mode and 15 KW is correct, what it says in your boiler manual is below. Put the boiler into test mode use P.01 and set to Hi. This is the only test for checking the gas rate of your Glowworm betacom2 combi boiler. it checks that the gas valve is only allowing that amount of gas to be used and that its not a 40kw boiler because the valve is faulty and its the only way. Perhaps you would like me to point you in the direction of the manufacture and the Gas Safe Register. Your test method failed to prove the above end of story. 11.6 Gas rates IT SAYS "GAS RATE" nothing about using analyser. i IMPORTANT: Due to the modulating operation of the boiler and the need to check the gas inlet pressure and measure the gas rate at maximum rate, it will be necessary to force it to maximum. • Activate the test mode "P.01" and set the value to HI in order to force the burner at P. max. See chapter "Specific adjustment > Appliance technical settings and parameter* list > Test modes". AND 11.6.2 Gas Rate • Make sure that all other gas burning appliances and pilot lights are off. • Check the gas rate using the gas meter test dial and stop watch, at least 10 minutes after the burner has lit, see table below for approximate rates. Gas rates (G20) Gas rates (G31) (approx) after 10 mins from cold MIN MAX m3 /h m3 /h 28kw 0.88 2.96 • Gas rates for both central heating and hot water can be verified using the test program P.03 and P.01 respectively. Code parameter* Description P.01 Forcing the adjustablepower burner when heating The appliance functions at a power adjustable from "Lo" (Lo = Pmin.) to "Hi" (Pmax.) by using buttons or after successful ignition. P.02 Forcing the burner to heating ignition power P.03 Forcing the burner to Heating Pmax. The appliance functions at its maximum power P.06 Venting the installation.
@@derekclark7545 do you feel better now ?I know what the book says at the end of the day like I say in my video if you think you are testing the boiler using the p settings that’s fine you do that but I like to know what the boiler is doing and if there are any faults with the boiler working at it’s normal working load. As you are probably aware most combi boilers in the U.K. are massively over sized for the property and will probably never get to its maximum load due to poor flow rates at the tap. When I train my trainees I show them how putting the boiler in force fire can make you miss faults on the boiler ie blocked plate broken diverter vale etc and I train them to gain an engineers judgement. Also another problem we have is small systems so most of the time the boiler will knock off because it’s up to temperature and won’t run for 2 minutes so don’t tell me you don’t just turn on the tap when that happens . Thanks for your comments cheers
@@tomkatgastraining Any more stupid comments, we are talking testing the gas rate in hot water mode using P SETTING AS THE MANUFACTURE SAYS not running the heating and some crap about diverter valves.
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Most of the decisions we make in the field are open to our judgment and interpretation of the regs, on site situations and manufacturers instructions. I would much prefer someone like Mr Hunt to contact you privately to discuss a query rather than points score and make you out to be wrong in public. Your videos are spot on for us all to reference and make decisions on the day so keep them coming especially for the new entrants. Some people are visual learners and they take a lot more in from these videos than a book and gives them the confidence to get through the ACS. 👍
Derek, we work in an industry that is open to interpretation, personally combi gas rating I usually rate hot water as the max, as you say potentially it can help highlight faults, like blocked plates, not all boilers on max setting show the full hot water input, due to range rating etc. I do the max whilst doing the FGA but usually do a final as left gas rate, in hot water for combi boilers, standard heat only put both on and do a final then. Keep doing what you are doing, we are all gas safe registered, and at the end of the day, unless like you say you are a trainee, we all have our own understanding of things and over the years build a sound engineering judgement, providing we have followed updates and used everyday as a school day and learnt through our journey. I was a trainer for many years at British Gas, our guidance was printed in the old operational procedures, so most of the time was pretty sound. In wider industry it’s different the written word isn’t there for every task you come across, there are different guides with varying interpretations, so at the end of the day all we can do is talk to each other, keep up to date with changes, and get through doing what we think is best practice. Keep up the good work, and stick to what you think is correct, like most trainers if there is anything you doubt I’m sure you will dig deeper for conformation just to clarify you are passing on the correct information to your groups of learners 👍
I am a trainer too and I agree with you. The 5 and 10% I use with students because you will never get an exact figure to match the MI’s, therefore, an inexperienced engineer will likely think there is a problem with the appliance. We have to remember that when boilers are tested they use a rig giving consistent CV’s and installation parameters so all boilers are tested the same. I used to do gas audits as well and if I saw a gas rate or heat input exactly the same reading as the MI’s on their gas safety certificate I knew they probably had not even carried out the test. Obviously you can’t prove it but it does give you a concern regarding the individual. Thanks for sharing the video.
Got to say I’ve been taught to gas rate in high and low and……. After watching this I realise what your saying is far more beneficial and gives me way more information about what the appliance is actually doing 👍🏼.
Mate you’re great !!! I’ve learnt a lot off your videos. Thanks for doing them 👍🏾
Brilliant video Derek, I have always done a 10 minuet warm up the CH test the rate on MAX next HW flow is OK then on MAX rate, works for me for 50 years.
Well done Derek. You could not have made this planer and easy to understand. That fella certainly has the right name
Not long passed my tests to become gas engineer found your videos very helpful can’t comment against people having a go as they probs no more than me but I’ve found your videos very helpful as have a lot of others keep up the good work
Great investigation again Derek - once again great explanation - keep up the great work.
Great video Derek........ thanks for teaching us the proper way to gas rate boilers.
Hello! As always great vid! I was always under the impression that rating in HW & CH have you the rate in a more really life situation? How the customer will actually use the appliance! They won’t ever put it in engineer mode! So I agree with you!! 👍👍
I always understood it that on Commissioning you follow the Manufacturers Manual and fully complete the benchmark where applicable (Gas rate (min and max to me, means service mode, (as most manuals show this) which will put the unit in to min and max mode directly)), Combi cold water temp, dhw temp and the flow rate stated for that appliance, as well as all the other information required, For servicing ALL manufacturers manuals have a section on the recommended way to service their appliance (and what to further carry out if it fails the fan depression test), and like you say, LPG do not always have meters, so the co/co2, ppm, fgt, efficiency and ratio will tell you a lot. Maybe you should just put a banner up at the start of some videos with a disclaimer mainly for the one who commented then removed the comments (did he realise he was an a**h*le). Keep the vids coming, :) very good video :):):):) deffo thumbs up from me.
I'm with you 100%!
When I do gas rating and flue analysis, I write down the various test results, at the meter ,boiler and taps. I feel that I'm more likely to spot any issues this way because all of the figures are in my face and as they are all interrelated, any anomalies will leap off the page,rather than saving logs and printing separately, if that makes sense!
Anyway, understanding what you're looking at is the key!
👍🏻
As a newly qualified gas engineer I must admit I have always been a bit confused about this, It seems I was not alone! I can see why gas rating at max rate would remove the unpredicatability of the boilers modulating effect on gas consumption but the point is we want to see how the boiler is actually performing. I have found that in some installations putting the boiler on max rate causes it to overheat and cut out before you can gas rate. Likewise in properties with low cold water supply flow rates the boiler moldates down to maintain a consant hot water temperature, the same can occur on hot days with the central heating. So what is right, to be frank I am still unsure. At least if you put the boiler into max rate for the combustion analysis and do a gas rate at the same time its consistant and you can compare the gas rate with the CPA results. Please dont shoot me down in flames I genuinely want to be better informed.
When analysing I run the boiler for between 15 and 30 minutes before i take the readings so I gas rate first not at the same time so I get the correct readings.
Most boilers now you can pull diverter head off and run the tap thst way on max it won’t get to temp and shut down
@@Silenced2024 baxi vokera viewsmann I tried it on a British Gas Worcester 542 fucker wouldn’t work kept locking out and over heating shoved fga in quick time had keep turing it gas off and running hot tap cool plate and heat ex down hate worcesters with a passion cut myself 3 times changing left block
I normally gas rate in test modes (where available), but I'm doubting my life choices. I can see both sides of the argument and seeing how a boiler performs in situ makes a lot of sense. 🤪
You are offering a great service. It is interesting that there are different options on many areas. I appreciate you taking the time to review it; you are right.
Just do what it says in the manufacture instructions , vaillant ,Worcester ,glow worm all ask for gas rate in max mode , that will do for me.
A plumber's perspective here...
If I talk about what I understand better (to keep it simple and avoid talking about things I don't understand properly), I'll focus on an old non-modulating boiler that is designed not to condense.
If I find a customer's heat-only or system boiler is gas-rated so low it won't reach the set flow temperature with all TRVs on max, I might suggest it's probably under-rated and needs a RGI to increase the gas-rate.
However, if it only struggles to get to that temperature when the DHW cylinder is also calling for heat, then it might depend on how often that is likely to be the case. If the DHW cylinder is only being heated once a day, it may be worth considering whether it is really an issue, provided the flow is sufficiently hot to get the cylinder to temperature (so, no less than 70°C, say). It is also worth considering that it is unlikely that the TRVs will usually be set to max in normal use. Normal use may result in the actual heat demand from the boiler being considerably lower than the full output of all rads at DT 55 plus cylinder coil on a cold cylinder (most people with zombie boilers rarely run them at 82°C anyway).
So, in a way, if the zombie-boiler gas rate is set too low to allow a flow temperature of 82° with a cold cylinder and TRVs set to max, but high enough to heat the cylinder and avoid condensation on the heat exchanger (say 70°), it may well be a perfectly sufficient gas rate (especially if the radiators are oversized), and possibly better than having the boiler cycling in 95% of real-world conditions. In these circumstances, I'm not sure I would bother suggesting the customer get a RGI to increase the gas-rate.
So, in my circumstances, I'm looking at what the boiler is doing and is likely to be doing. I.e. taking a practical approach rather than slavish observance to somewhat pharisaical rules. Particularly if those rules are not enshrined in law.
So although we are talking about slightly different things, I think we agree on the general approach, which is that the boiler should be set up so it is running in favourable conditions for the majority of the heating season, and not under hypothetical cirumstances that may only exist under arbritrary test conditions.
I feel its good to do it in max and min as its the worst case scenario and i feel thats what looking for
With the new buildings going up every where in my region of the uk we are finding that the local water authority have reduced the water flow entering properties as well as the original installation engineers are fitting flow regulating valves and pressure reducing valves and then finding they are fitting 35 kw boilers in 2 bedroom properties/flats in these instances checking gas rates become a mine field and a lot more working out is required. You cannot achieve the the correct kw nett reading within the tolerances stated. The equation for doing it traditionally would need to be adapted based on the specific flow rate at the property.
Hello. Would you use net cv rather than gross cv for gas rating if its a condensing boiler? But if not use gross?
Also, in table 2 for CH gas rate. What is the relationship between the top row of numbers and the ones underneath?
Is the top row(26,32,40) showing three different size ideal boilers and how much kw they use on high central heating setting? With the row beneath (18.1,26.1,32.1) showing you how much lower than the optimal rate of gas is allowed?
Only thing im in two minds about is.. depending on the system and when the boiler was last in use you will get different gas rates all the time on CH with a modulating GV. So I always thought the point of doing max gas rate was to indicate if the boiler could burn more than it should be possible to, indicating it could potentially do it in normal operation and cause a fault/damage. Min gas rate usually locks out if not set correctly and/or will show on the FGA that its not to MI's but again i thought the min setting gas rate shows that the boiler can operate correctly in its lowest state. That's why it made sense to me to test in min and max on a service visit cause parts can wear out as you said. But im no trainer so this was interesting video and very thought provoking in a good way. Keep these videos coming 👍🏽
Nice and clear. Thanks Derek! 👍🏻
GR at Min rate is a good idea, I've been to a few Vaillants that have been messed with and they were a KW out, not good when we need low modulation
It does give you the max and minium kw output in the manufactures book ,so that gives you an accurate figure you need to be close to .
I set the boiler to min, then take FGA. Then I set it to max, take the FGA, then do the gas rate at the same time. However in the summer I’ve had days where I can’t keep the boiler running long enough, even trying to GR with the room stat at max. In those cases I will use a tap and GR to that rate instead. It’s a case of using my judgement.
I have this same problem, i always would do Minimum 1st, than max, otherwise it takes ages for the readings to settle down. Did this in front of a Gas Safe Inspector, and his reply was to to my manager was Do you guys ever read the manuals? So i have always done max 1st then min. but on small systems, i always run the hot tap for 10 mins, to allow for the boiler to warm up 1st
Most condensing boilers say gas rate in max mode.
This makes sense as it’s a set test.
How can you gas rate a boiler that’s modulating and get a reading worthwhile.
How ether in the benchmark you could do it in heating and hot water as that’s what it says and it’s just a commissioning test.
On Worcester 8000 for example on commissions can have
The only problem with not putting the boiler in service mode when gas rating is , if you have poor flow rate at the taps the boiler will modulate to quickly and will under perform on the gas rate .
You need a good water flow rate to get the hot water performance.
I gas rate on max always have done just to check it’s giving me the right kw for the boiler I also do it when I range rate a boiler aswell as fga results
I've had lots of conversations about this subject and have never heard the same conclusions drawn. Essentially, as far as I can see, the gas rate when combined with burner pressure in an old fashioned machine is primarily checking for either a blocked or worn jet. In a modern boiler, assuming no intake or combustion gas flow obstruction or anything that causes downward modulation, this same check will confirm the correct operation of the gas valve, so, surely, checking at any know datum point, max central heating, max dhw, or any stable and known load will give a result that can be used to make this assessment.
I do gas rate in Max to look at performance and compare to MI’s. Most manufacturers ask for that. I then gas rate in hot water and CH to see what’s actually going on. The CH gas rate can be useful for range rating modern appliances
Also keep up the good work been watching the videos since you stated really helps in keeping the brain fresh thanks
Thank you for such a clear content, Tom!
I thought doing the test on max is to test the pipework is adequate to supply sufficient gas to the boiler.
Absolute madness that we’re all questioning gas rating… 💥💥💥
I hope there ain’t no customers who have just had a boiler fitted reading this 😂😂😂
Love ya vids Derek & yours Allen 👍🏻👍🏻
Good video Derek,
When I’m commissioning boiler I follow the benchmark an gas rate in Hotwater mode, usually open 2 taps to get maximum flow..
But when I was in training centre I was taught gas rating appliances under maximum load, but theirs was more for gas cookers, fires and older type of boilers what didn’t modulate…
I hate trying to Gat rate boilers on maximum with a small heating circuit as it shuts down an reaches temp to quick
If an appliance has max/min service mode, i only gas rate on max on a service, as your putting boiler flat out, so in theory its worst case scenario. If its out, more so below the 10 percent, then its showing me that theres a problem with the boiler like a blocked burner for example. On some CP12s out there, it gives you the option to record for both max and min, but again thats for fga. If its a baxi 105e for example it tells you to run hot tap for fga and thats when i would do my 26.9 checks on hw. Also if you have additional appliances on installation, they also need to be running so that you can determine that the meter can supply the correct amount of gas. If i was installing boilers i would be checking max and min, so i can say that yes, this boiler is correctly installed and working as it should. Your all over it Derek, so keep up the great work your doing.
Being 100% honest here if I have a problem with a trainer etc I would take it up with them directly not by being negative on they’re video.
As a gas boiler user, it worries me that someone is training people that may install my boiler in an incorrect way. You may a clear case for your argument and it seems watertight. I hope my new boiler , last September, was installed by someone trained as you were.
The whole point of gas rate is to see if your getting the manufactured maximum for the appliance and not forgetting if the meter is capable of providing the gas required without a drop of the supply pressure. Try getting your maximum on a hot day without your tap. Nothing wrong with doing both to see if it is performing correctly. The GSR are completely open to interpretation. It's down to the engineer. Each appliance and fit is different follow the MIs. CCN 1 leads on to Commercial change over. They don't have hot water. But you still need to Gas Rate. In the summer the best way to get load is run down your DHW cylinders. So each installation is different. Your the engineer its your gas card. But if you can clearly describe what you have done and why you won't go far wrong. My definition of a boiler is a steel bucket with a flame under its ar5e. You can complicate it as much as you like lol
Excellent defense and would be choosing you as an instructor than anyone else.
Cool vid Dman! Company i work for want GR (Gas Rate) in max mode. If no max/min mode then its with hot tap running (DHW) or central heating (CH) depending on boiler & system! 👍
Hi Derek. A big fan of your channel. For me personally, where the MI states that the gas rate should be done in high and low, that's what I prefer to do. But I have a question, if the gas rate is too high or too low (outside of the tolerances), but the combustion analysis is fine, how would you class the boiler? Would you say it's safe?
If a gas rate is too high then it’s ID but too low it’s just poor. As I say in the video why would you gas rate a boiler on high and low that just makes no sense to be because it doesn’t show how the boiler is working. Gas rating the boiler on water and heating will show if you are having problems high and low won’t show problems. Thanks for watching cheers 👍🏻
@@tomkatgastraining Fully understand and respect your position. It makes sense. Cheers
The success of other cause jealous.
This man TomKat, for long, is helping us a lot learning, understanding and be a professional GE on the field with a lot subjects. And he is doing them for free without charging any penny. Instead of the guy asks Tomkat in private and get in conversation and explanation, he came to put this brilliant teacher look like dumb.
I am on my way to do my ACS, and apart from my centre training, Tomkat and Viva training academy are my reference and I say Tomkat is my main one. I can refresh, learn and be ready for all subject through this man Tomkat.
I will say Tomkat just ignore this thinksmart man and keep doing what you do. I everytime say to my teacher at C.traing that we got a good RUclipsr teacher Tomkat and He says, yes he is a great and good engineers.
Thank you for everything you provide for us. May almight bless you.
Have the same problem with working pressure cadent test on hot water we test on maximum had to call them out not getting enough pressure at meter on max they test on hot water and say it’s fine manufacturer says has to be turned off cadent say it’s fine where do you stand then 🤔
Yeh it’s a big pain in the neck. At the end of the day the boiler might never get to its high rate especially if the boiler is massively over sized and the house has poor flow rate this is where our engineers judgement comes in after we have carried out all our tests to see if it’s a boiler fault or installation fault.
I totally agree with you for central heating mode but with a combination boiler you would gas rate at full rate on commissioning and enter that in the hot water section of the bench mark. If servicing a boiler you would check its gas rate on full load during flue gas checks before you you look into boiler setup . Gas rate in range... tick , flue gas analyser correct ratios ...tick, max load and min load ppm...tick, and now you will know if you need to go deeper. the bench mark hot water section clearly states at max load and your tolerances at max load are clearly documented in many manuals as +5 and -10. old bulletins that are no longer in circulation maybe out dated or revised.
If you are gas rating in full load how would you know to go deeper. In my service video I had very low gas rate on hot water so I checked temperature and flow at the tap. The benchmark states max load on hot water and I have never seen the 5 and 10 % in a manual. Maybe I am looking in the wrong place. Like a said in my videos if you can say with confidence that when you check the boiler the way you do it is correct then who can argue with you. Cheers 👍🏻
@@tomkatgastraining thanks for the reply. Bench mark hot water is at full rate you can see that clearly in brackets. tolerances are in all Vaillant and their glow-worm boilers its a standard allowance IMO , if outside of that then you would go deeper ...pipe damage restriction .Inlet pressures etc etc. re the LPG gas rates all manufacturers state 37mb and don't give tolerances probably as a safety line due to bottled supplies but you can weigh gas used and do the math...only joking. we know what the allowable drops are at reg etc so I guess we engineers can use common sense. keep up the great work its great to refresh stuff and discuss
@@geetee50 dose it not mean full rate of the hot water it was written like that before we had condensing boilers should it not have been written differently to make it more clearer.
A guard over condensing flues below 2mtrs is the only rule I think could be updated, I was told what if someone blocked the flue way when I questioned it . That's a bit weak I thought ...stupid rule IMO it should just be a plumb kit must be fitted below 2mtrs.
@@geetee50 kind off is but you still need a guard under 2 m even with a plume kit
I did this when having my gas-safe inspection …,, the inspector was in total agreement ….enough said
So to gas rate on heating and hot water would you set the temperature for each at the max on the boiler and then gas rate by turning them on at the programmer individually
Isnt a gas rate to
Check if the gas appliance is burning the correct Amount of gas? So if a 24 kw boiler is giving u 18kw you know theres an issue somewhere with the boiler most likely the heat exchanger
Another Great well Explained video Derek. Have you thought about doing some Q & A videos with Gas Safe / Manufacturers?
I have but don’t have enough subscribers for them to bother with me
Ideal logic plus boilers 30kw specifically mention testing gas rate in dhw mode not high rate service mode.pg 37 under general checks 40
Do we need a ticket to work on a aga
Im gonna be totally honest. When I first started, I used to gas rate every condense boiler on high rate, when there were two of us. But as time went on and I started to work alone more I couldn't do it as its a 2 man procedure.So I stopped. Now I work in more commercial properties where you cant just interrupt the gas supply at a whim, still not doing it.
Same. I installed some commercial boilers 4 months ago, they were manufacture commissioned, he didn’t gas rate them. So hard to gas rate in commercial, with kitchens and other appliances on.
Great video again, what would you do if you try and gas rate on hot water but the taps are rubbish? Would you then just gas rate it in high fire
I wouldn’t I would just note the rate for the water because if the house has poor flow or water saving taps the boiler will never go in high rate
I get you completely.
You are both right in a way.
However if you go of all literature you are more right than Michael.
It all depends on the situation you are faced with.
Whether you are commisioning a new boiler install or whether you are servicing an old boiler.
I must state that peole dont like being told their wrong (human nature maybe) dont take it to heart, Michael just has some growing up to do / improving the way he conducts himself.
All the best and thankyou for your uploads as it does keep me on my toes.
This needs discussion for proper conclusion in pub after 8 pints .cheers
like you said you wouldn't know if it was LPG l wonder how many engineers actually do a gas rate when they do a boiler service?
Hi Derek, just started service/repair work. I was taught to gas rate on high on low as it's the co2 readings of these readings we need to set/ adjust gas valve. Work exclusively on WB boilers. Their MI's always state service mode for taking readings.
I'm confused.
As I say in the video do as you feel fit you are the engineer. As long as you can determine the appliance is safe and working correctly then carry on doing what you do no need to be confused
@@tomkatgastraining Brilliant vid though.. Just goes to show need to adopt a more sophisticated approach and understand what/why you're doing something rather than mechanically going through the motions.
I'm going to spend a bit more time going forward and maybe test a bit more and get more readings and have a proper think over them.
Keep em coming Derek.. appreciate your efforts!
I only put the boiler in service. Mode too Analyse ….gas rate as per bench mark …..👍
Should the question be... 'what method did the manufacturer use to obtain their figures.' Shouldn't we be using the same method as the manufacturer used, to be able to make a comparison ..? The manufacturers figures you show us, show a figure for Central heating and hot water mode. Therefore we should be checking in the same way.
can you make a video on gas rating and how what to look for when taking the values? How to interpret the values and if there's a problem what to look for?
Already done quite a few on gas rating check out the playlist on the channel
@@tomkatgastraining cheers mate, I was looking but most of the gas rate videos cover how to gas rate, unless I am not seeing something. I was hoping to find something where you explained more as to how to interpret a gas rate value when there is nothing wrong and when there is something wrong, if that makes sense?
i went to service a new baxi in a caravan last week.it had 5 rads.when put into high gas rate,it took 3 mins for all rads to be bouncing and i couldnt carry on. the flow rate was so crap at 6 litres it wouldnt modulate fully for long enough.so i used my 35 years of experience to ascertain after a combustion test high /low ( as good as possible) that was safe to leave working..
Best endeavour
Genuine question here. What do you do if you gas rate a new appliance and it ends up being too low? Replace appliance under warranty and install at own cost? Maybe manufacturers reinstall new appliance?
The gas rate is just one of the test to prove the appliance is safe or correct. It’s all about understanding the results at the end of the day
There is no mandatory requirement to gas rate but i would always gas rate in high if the boiler allows that, ( depending on the manufacturer's instruction ) Personally i don,t agree with how you did it in your service video and i wouldn’t do it that way. Also, some of the AR and ID you claimed in other videos were also incorrect. Anyone watching any videos on youtube need to check for themselves with the manufacturer of the boilers as things vary with different manufacturers and different models of boiler. No one is correct all the time and sometimes if you phone the manufacturer they can also give you incorrect advice, Keep up the good work.
Wow I feel so honoured that you put a comment on one of my videos even if it is to have a dig 😜
@@tomkatgastraining Do you ever go on manufacture training days? next time you do let me know and i will come with you. Lets go to Vaillant and we can ask them if your video is how they train out.
@@tomkatgastraining as you know i have experience with both centres and it would be very easy to do videos slagging other people off. Not really good for the new trainees though. I actually thought better of you.
@@AllenHart999 if mr hunt wasn’t so rude with his comments and then remove them I probably wouldn’t have done the video. Yes I do go to manufacturers training days and I have been to Vaillant on numerous times and I know they quote the 5 and 10% even quoting the British standards but again in my video I didn’t say it was law I said what I do like you do in your videos. Please make your video about me being wrong with the ID and AR but don’t remove my comments like you do in your other videos when I make a comment.
@@tomkatgastraining I Would never make a video about you being wrong but you are welcome to call me anytime and I would be happy to tell you. Has any manufacturer ever told you to gas rate and not use service mode? Your service video was unlike anything i have ever been trained and i have been to almost every manufacturer for training. Lets go on a Vaillant day and both film it???
Ive had some problems trying to gas rate on these new builds . The meter turns off to quickly . .
I have a video on gas rating with the new meters so go on the channel and check it out 👍🏻
As Derek says, Gas rate is real world test on what the boiler is doing at that point in time,remembering it's in relation to a service, I'll go with Derek 100%, be interesting to see "mikes" vid. (oh hang on !)
I don't think Mike hunt is his real name he's talking the piddle. If he's that good why don't he make a video
It’s very unfortunate if it is his real name
I have trained with both trainers and at both training centres.
@@AllenHart999 and???
Mike Hunt should name his training centre so we can all avoid it and qualify and update our ACS correctly
It shut down last yr
What if the boiler as been range rated down ?
Opinions or common sense keep up the good videos ignore the training trolls
If you look at the benchmark ….it asks for gas rate. In central heating. And in hot water …enough said 😃
When you go on a manufactures training courses they nearly always tell you to use the service mode settings, Otherwise, why would they put them in boilers.
Thanks
Sometimes people over think this and there certainly is some some confusion and misconception over what is the “ correct “ method of examining the heat input of an appliance
Mr Hunt seems to be 100% sure that he is 100% correct and that you are completely wrong but as you have demonstrated there is more than one way of achieving the results you need
I personally prefer to measure the heat input on a combi in hot water delivery mode but as long as you can demonstrate that the boiler is delivering the specified outputs then either method is acceptable
As you have also pointed out ,sometimes it may not be possible to examine the heat input of an appliance , e.g LPG installation or you could also have a situation where the electronic meter display is faulty and readings cannot be obtained
I firmly believe that if you follow what the manufacturer says, work in accordance with the regulations and apply your own professional judgement and common sense to determine if an appliance is operating safely and efficiently then you won’t usually go far wrong
Flue gas hi and lo, gas rate ch and hw mode. I am also a trainer.
Excellent 👌..gas rate in hw and Ch ..
Phone the manufacturer and ask them if it's required or not.
@@AllenHart999 great idea , great to see you getting involved with this my good man ..very interesting subject ❤️
@@jockster5525 Derrick is been very unfair doing this video tbh, in my opinion, it makes him look bitter. We all do videos where we get things a bit wrong, I would always advise to check with the manufacturer, Go on manufacturer training days, What Derrick put in the service video is unlike anything any manufacturers have ever told me, We were not trained that way at British gas either.
@@AllenHart999 hi Allan. Thanks for your input. I could write a long winded reply to this but it'll probably be wrong ☺️ we all have systems and ways of working , I always try to follow the manufacturer scripts and texts , I usually get things right but always open to interpretation and learning from all . Every day is a school day . My tutor is none other than Adrian brown in saffron Walden , a fantastic man who has a great way of teaching and makes it fun and enjoyable. Not sure if you know of Adrian,he was a British gas trainer I think.
I'll be running these opinions out to him very soon .
Is that Michael hunt still waiting for his taxi
Michael hunt runs ngcfe not sure if its him in the comments but he does a lot of videos with allen hart on youtube
There’s always a nutcase in the woodwork somewhere who thinks he’s an authority on the world!
While this is an interesting discussion the importance of this is overstated. Probably 95% of boilers never get gas rated when serviced or when installed for that matter. Engineers just don’t bother.
I feel for you derek, trying to do something beneficial, and time and time again, you get unnecessary abuse.
This is pretty simple this, pretty simple indeed.
FGA in high and low, to check parameters of the boiler, and for comparison with the MI’s.
Gas rating in high and low, and for the benchmark, in high CH also. Because in most circumstances, high is for HW and not CH.
As you rightly point out, because it’s modulating, either by itself or by means of load/weather comp, it’s difficult to accurately get right, but it is a useful guide to demonstrating the boiler/controls, parameters of the boiler, are working correctly. Engineer’s judgement indeed, is that so difficult to understand??
MISTAKE mike’s surname starts with a C. Derek it pains me to see you get upset by trolls, come on fella let this one go he’s not worth it.
👍 Sue Warrington
The reall question is. Do we even gas rate?
Call out for Mike Hunt please
I’ve been taught gas rate max rate heating or gas rating hot water …. Then f g a. In minimum and maximum settings. Don’t see how you can go wrong.
Seems a lot of different opinions in the comments……Think this could make a real good informative video, Tomkat, Allen Hart, Gas Safe rep, boiler manufacturer trainers?
Hw if flow rate good & ce
Mate book an holiday,
Making blow back videos on a Sunday to other tutor’s,
Too much jealousy in this business mate carry on making money your doing well
I wish I was making money I made more money on the tools than I do now 👍🏻
Has anyone even seen Mike Hunt?
A bit of a eye opener, but as usual your thorough explanation goes a long way to convince me that your as usual.... More right then most right wing politicians 😢 Ever thought of a job in politics?
Derek Gas rating is not finding out the kwh. its finding out the cubic meters used. what you described is finding out heat input. cheers Rob
just my opinion and not an attack
We turn the ft3 or m3/hr into kw don’t we 🤔
@@tomkatgastraining yes but young uns and newbies i have worked with dont understand that heat input isnt a gas rate. i have asked for the gas rate and they come back with heat input when i needed the cubic meter. Even on commisioning sheet asks for cubic meters.
@@Heatingandplumbing1 you are correct in the benchmark only asks for the ft3 or m3 and I guess it’s poor training if new entrants don’t know the difference.
That guy is trolling.I'd bet he isn't a trainer or even an engineer.
He knew about TB 141 which hasn’t been about for years so guess he has some training experience but I could be wrong
only one troll in this video, Very sad that Derrick has chosen to show other trainers in videos to try and pull them down, Could of quite easily just blanked the name out.
@Tomkat Gas Training Just to be clear you said the +5% and -10% mean nothing but it is an absolute in Vaillant MIs. Not a guide. And Vaillant only require gas rate on max. All MIs are different and they all have their own quirks.
We just need to be on the same side and not slating each other for not knowing everything but be more open minded 😃
E.G. Ecotec Pro Page 34 Table 5.1, etc
I didn’t say it means nothing the 5 and 10 % I said it’s not in any regulations but it is a good guide if you are new into the industry with no engineers judgement.
@@tomkatgastraining Hi Derek, I use your videos for training and support your channel. My point was don't tie ourselves down with any 1 Manufacturer and be aware that they really do have different requirements and use different wording.
Again Vaillant insist on Gas rating on Max to get the consumption.
As you would say, we know when something is wrong due to our experience. Keep up with videos Derek, you're doing a fine job.
God help any of us who go to Mike Hunt's training centre.
😂👍🏻
I have trained at both. We could all do videos like Derrick has done today naming people, Its quite sad tbh as i could of done the same with the AR and ID video Derrick did but we need to help the industry and not fight between ourselves
mike hunt is literally that..
😂
👍🏾
mi before i even see vid.
I would not use Ideal boilers as a example, they tend to leave everything open to interpretation, not so long ago they never had a means to force a boiler into full burn rate.
There are several manufactures who state that you need to put their boiler into full burn rate and low burn rate for various tests and also tell you what the 10 and 5% figures should be with consideration to other factors.
The Bench Mark now requires full burn and low burn Co2 % and Co PPm for which you need to put the appliance into those modes to obtain your figures. I can also show you Bench Mark books that require ratings in heating and hot water.
Below I have taken examples, some parts are missing as I don't need a war with the manufacture *
▶ Measure the gas flow rate at _____ gas meter.
▶ Compare the measured values _____ the corresponding
values in the table. *
H gas in m³/h
Nom. +5% −10%
15.3 1.62 1.70
18.4 2.05 1.76
24.7 2.61 2.74 2.35
25.7 2.72 2.86
28.6 3.18 2.73
30.6 3.24 3.40
78 3. 97 3. 40 * The manufacture is telling you how to do the tests in full burn rate and how to use its programmes to fill in the Bench Mark.
If the manufacture says these are the values, you are working to this like it or lump it as in court you will have no argument.
Your not going to be working any other way when you install this boiler, or when you service it, there training centre will tell you the same, follow these procedures.
Using check programmes
P.00 Purging programme:
P.1 Maximum load check programme:
After successful ignition, the Boiler is operated at
maximum heat input.
P.2 Minimum load check programme:
After successful ignition, the Boiler is operated at
minimum heat input.
* Yes, some wording is changed and some numbers are missing, I don't need a war with the manufacture.
My Opinion, Do as the Manufacture says. That book and the Manufacture is God in Court.
Maybe you need to fit a new and different boiler every week Derek because they all have slight variances on telling you how to commission and service their boiler. If you cant achieve the KW rating at full burn rate in the mode the manufacture says, within the tolerance allowed, the gas supply is not correct and the appliance is At Risk. You need to go back and look at your video, I think you set a poor example when gas rating your boiler as do other reading through the comments.
You are missing the hole point of the video. Mr hunt said every boiler manufacturers say and every manufacturer must do. But as you say not ever manufacturers are the same my hole point of the video is to follow manufacturers instructions but also understand what figures you are getting and act on what you see. We are supposed to be engineers so let’s be one instead of being sheep
@@tomkatgastraining Just for you as you failed to test the boiler as per manufactures instructions, no where does it say in hot water or heating mode and 15 KW is correct, what it says in your boiler manual is below. Put the boiler into test mode use P.01 and set to Hi. This is the only test for checking the gas rate of your Glowworm betacom2 combi boiler. it checks that the gas valve is only allowing that amount of gas to be used and that its not a 40kw boiler because the valve is faulty and its the only way. Perhaps you would like me to point you in the direction of the manufacture and the Gas Safe Register. Your test method failed to prove the above end of story.
11.6 Gas rates IT SAYS "GAS RATE" nothing about using analyser.
i IMPORTANT:
Due to the modulating operation of the boiler and the
need to check the gas inlet pressure and measure the
gas rate at maximum rate, it will be necessary to force it
to maximum.
• Activate the test mode "P.01" and set the value to HI in order to
force the burner at P. max. See chapter "Specific adjustment >
Appliance technical settings and parameter* list > Test modes".
AND
11.6.2 Gas Rate
• Make sure that all other gas burning appliances and pilot
lights are off.
• Check the gas rate using the gas meter test dial and stop
watch, at least 10 minutes after the burner has lit, see table
below for approximate rates.
Gas rates (G20) Gas rates (G31)
(approx) after 10 mins from cold
MIN MAX
m3 /h m3 /h
28kw 0.88 2.96
• Gas rates for both central heating and hot water can be verified
using the test program P.03 and P.01 respectively.
Code parameter* Description
P.01
Forcing the
adjustablepower burner
when heating
The appliance functions at a power
adjustable from "Lo" (Lo = Pmin.) to "Hi"
(Pmax.) by using buttons or after
successful ignition.
P.02
Forcing the
burner to
heating ignition
power
P.03
Forcing the
burner to
Heating Pmax.
The appliance functions at its maximum
power
P.06 Venting the
installation.
@@derekclark7545 do you feel better now ?I know what the book says at the end of the day like I say in my video if you think you are testing the boiler using the p settings that’s fine you do that but I like to know what the boiler is doing and if there are any faults with the boiler working at it’s normal working load. As you are probably aware most combi boilers in the U.K. are massively over sized for the property and will probably never get to its maximum load due to poor flow rates at the tap. When I train my trainees I show them how putting the boiler in force fire can make you miss faults on the boiler ie blocked plate broken diverter vale etc and I train them to gain an engineers judgement. Also another problem we have is small systems so most of the time the boiler will knock off because it’s up to temperature and won’t run for 2 minutes so don’t tell me you don’t just turn on the tap when that happens . Thanks for your comments cheers
@@tomkatgastraining Any more stupid comments, we are talking testing the gas rate in hot water mode using P SETTING AS THE MANUFACTURE SAYS not running the heating and some crap about diverter valves.
Michael Hunt sounds like a ....