Clearing an
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- Опубликовано: 23 мар 2021
- If you are put off draining your heating system because of airlocks afterwards. Here are some simple solutions.
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Hi Al Great Video as usual an old trick of mine was to fill the system from the drain off cock from the mains hosepipe (make sure your tap has a check valve) and regularly check the level in the F&E!! You can also use this method to clean the system as well make sure you use a hose clip on the drain cock. On one job I had a huge problem with an airlock on a gravity hot water system pumped CH. The CH was OK but no HW so I connected a hose to the vent on the F&E and a huge air bubble came up through the F&E. Don't use these methods if you have a Primatic cylinder. Finally manually open all motorised valves on drain down. All the best Al.
Some great tips there Michael thanks.
A very useful plumbing video. I was really struggling with air in the system after replacing a radiator until I watched this. Very well explained and it fixed it straight away. I tip my hat to you sir!
No problem.
Thank you very much for your advice Alan.
Bled the motorized valve in 5 min. and it fixed non working central heating immediately with no air in any radiators.
Couldn't believe I've not come across this problem before.
Many thanks again.
Excellent! Well done Tony.
Just watched the video . Had an airlock on a ground floor radiator, after fitting a new one else where .
Did what you advised in the video by turning 1st floor rads off , air lock gone . Brilliant keep up the great work cheers.
Glad it helped
Not unexpectedly, 2 rads cold after draining system for 3 rad valve replacement. Luckily both of the rads had a drain valve on them, so I was thinking if I could use them to help flush air out. This video showed me that it was possible and indeed 10 minutes later I had hot rads again. Other videos just show you one method and if your system isn't like theirs, they wash their hands. Donation made 👍👍
Thank you very much Martin.
Good stuff. Always good practice to lock the lever on any motorised/ mid-position valve to 'manual' to encourage the air up the vent.
Thanks.
Thats better big al, very informative 👍 back on top form.
Thanks 👍
Great tip on bleeding the 3 port valve, had some air in mine that would stop the flow to Ch after a few minutes and you'd be fooled to thinking it's a mechanic fault! 👍
No problem.
When I have worked on my heating system I have put a bung over the outlet of the expansion tank. I then have opened the drain valve and waited until water stops flowing usually a few minutes until vaccuum has been created. Once you have done this you can undo any fittings and very little or no water will flow. When refilling the system I have attached a hose from my garden tap which is mains pressure to the drain cock and held it on tightly with a small jubilee clip and then turned the mains back on but not full on. This way the water will flow slowly upwards pushing any air out in front of the rising water. Once water is emitted from the expansion overflow turn off the main and remove the hose from the drain cock and tighten it. Good idea to bale out the excess water on the expansion tank. Doing it thus way the system will be full of water with no airlocks.
Great info thanks, it might pass it on in a video.
@@dereton33 Can you please let me know when you do a video for my suggestions. Thanks
Thank you so much Al - so helpful. Ever since we had to replace our boiler and the engineers ended up needing to drain and fill the system 3 times!!! I have noticed so much noise when the central heating comes on (F & E, convection boiler) and all of the radiators are noisy, cold at the top and needing constant bleeding. Can I now be sure that the cause is an air-lock? I couldn't put my finger on it before! The engineers mentioned an auto air vent has been fitted in the new piping next to the boiler, but I guess this isn't enough to avoid the problem?
You are drawing air into the system which is ending up in the radiators. Did you have the system cleaned before the boiler went in. ?
@@dereton33 Yep, the engineer said they used a cleanser, did a non-power flush and then added inhibitor. Thank you so much for replying Al :) I really appreciate it. In your opinion, roughly how much would it cost for someone to come back, try to diagnose why/where air is getting in from and try to fix/install more auto vents? (London) Is it a job most engineers would be familiar with?
@@islarodrigues1476 did you get this sorted? If the auto air vent was before the pump the high suction close to the pump could be drawing air in through that vent
@@funkypotamus Thank you so much for taking the time to message me - I really appreciate it :) Basically, I called in a gas and central heating engineer who charged me for one a half hour's 'labour' ;) He looked at my system and F & E tank and told me that the best solution would be to change to a closed system with filling loop etc. He did kindly suggest turning down the setting on the pump, which seems to have kept the problematic radiators hotter for longer (so reduced, but probably not completely eliminated the air lock?) as there is still a lot of noise from the loft and the system (his diagnosis was that air is being drawn in from the OPEN VENT - part of the F & E tank I presume?). The AUTO AIR VENT (which I believe is the little brass part installed onto the boiler piping) is on the END of the vertical copper piping next to the boiler - not near my pump thankfully, but perhaps it is not working effectively from this position either!?
@@islarodrigues1476 if the pump is near the f+e vent it could well be drawing air down that vent
I had a radiator removed by a plasterer (so he could do behind) and as he couldn't turn it off (faulty TRV I think) so we had to drain the system (learnt how from one of your videos) and took opportunity to fit a new towel radiator and replace another rad with a vertical one. Ever since, air in the system. Bled pump and bled rads (your videos again!) and now balanced (yep - your video help) - but air still comes out of 2 rads every day - just cannot get rid of it. Been bleeding now for two weeks on and off. Also, boiler seems to stop before thermostat temp is reached - but maybe I'm getting paranoid about that (as it's in my office and I hear it more working at home). The two rads "gurgle" when the heating comes on, during heating and when it goes off. Would you recommend I fit some autovents to the two rads to save bleeding. Your videos are amazing sir.
Yes you are pulling in air from somewhere, two auto bleed valves will sort it . You might like to try turning the pump down to it`s lowest speed setting to see if it stops pulling down air from the vent.
Good explanation once again Al 😎 we have just had some work done on our system. Re plumbed the circulation pump from horizontal to vertical and installed a bypass. We have a automatically operated air valve on the hot water tank side of the three port directional valve. All radiators heat up fine but we appear to have a bubble moving around the system. We get running water style noise from different radiators but predominantly the hallway radiator. The plumber came back and said it was because the radiator is the one that is always on with two lock shields. He said is was because one valve was open to much and turned it down and said that should stop the sound of running water. Sadly it hasn't. I do maintenance at a school so confident on doing stuff myself. Do you think I need to fully drain down again as my wife said she thinks he didn't do like you suggested and opened all air taps the radiators we have 15! Sorry long winded pardon the pun lol
Well if you don`t mind draining down that many radiators, filling them back up and clearing the air, then go for it. It`s worth a try. By the way as you have a bypass fitted you do not need two locksheilds on the hallway radiator you can fit a thermostatic rad valve one side and shut it off if you want to.
@@dereton33 Thanks forward for replying. Over Easter job I think 🤞
tks for this.. I have a maddening issue where rads downstairs dont get very hot. Happened after an installation of a new heated tall towel rail upstairs. I have bled all the rads. When I turn off all the upstairs rads the downstairs ones get burning hot in seconds so I dont think its the pump. I have balanced them several times but always reverts. Still think its an issue with the new towel rad or air somewhere .
Just turn the upstairs ones on a quarter of a turn each, do them one at a time from off position, making sure the downstairs rads do not get cold.
Something you didn't mention is how to introduce the inhibitor on a combi system. Do you pour it though a funnel into a radiator? As the water flows past the rads rather than through them I was concerned that it would just stay in that rad and not get dispersed through the whole system.
Just use the funnel idea, once you turn the heating on the pump will pass the inhibitor around the system.
Wish this heating engineer was in my city!
Thanks Geraldine.
I have a weird problem, after adding a couple of new radiators to my pressurised combi system, one of them struggles to get flow. When I turn the heating on, the rest of the system gets hot, but this one gets nothing, pipes cool - despite being on a drop down leg of 15mm copper tee'd straight off the main 22mm flow and return. I turn the rest of the rads off and it gurgles and trickles into live, eventually getting scorching hot, then if I turn the others back on, it all works fine, then next time I get the same again.
Our boiler is a 1 year old 30kw ideal. Seems to get the water in the system scorching hot... there are 8 rads on it, but a couple of them are small ones and I've balanced as many as I can so they they are tightened right down, but left the problem one fully open - I'm pretty sure it's not a balancing problem.
There's no air in the rads and nothing comes out when I bleed them. I've flushed this rad by isolating it, then attaching a hose to the bleed thread and opening the valves then letting mains water flow through it. Some air comes out which is very satisfying, but it doesn't rectify.
There's a gurgling noise every time I turn the heating on that sounds like air, but I can't for the life of me see how there's air in the system if it's not collecting in a radiator over time. I live in a 3 bed semi so the pipes don't flow over great distances, nor is it very complex.
I also noticed that if I run the hot water (also off the combi), this can kick it into life a bit, by turning the hot tap on and off, then feeling the pipes I can feel hot water getting drawn down, as well as hearing a gurgling. I'm guessing that this could be a pump surge as the hot water to the tap slows down?
It might be worth noting that all downstairs rads are on drop down legs. Also for the record, I have put loads of inhibitor in as I was worried about gas build up from the new rads not being protected enough.
Any ideas? It's getting me down a bit.
Drop pipe systems are the worse systems to balance out. I will give you a link for balancing using the accurate temperature probes method. ruclips.net/video/1xwickv1N3c/видео.html
@@dereton33 thanks for responding! I’ll take a look… I’m fairly sure it’s not a balancing issue, but I’ll go through the steps in the vid to help get some more understanding. I’ve got a gun thermometer here which should do it.
Maybe an obvious question, we’re in a bungalow and have two drain valves outside to drain system, do I just open both?
Yes.
Hi. My central heating pipe is making a knocking noise. All radiators are getting hot. But fear theres air stuck in the pipe. Its about half way down a 20 foot pipe thats all soldered. When i nudge the pipe the noise goes briefly. Any ideas from yourself or your viewers would be appreciated. Thanks great video
Just put some more pipe clips on it.
@@dereton33 thanks. Your the second person who has said that. Thanks
Drained the system to fix a leak on hot water cylinder because the leak was coming from the CH inlet pipe. Fitted new drain valve on downstair rad because there was no drain valve.
Fixed the problem, refilled the system and bleeded the rads but due to air in the system, boiler starts but shuts down after running for a 30 seconds, showing some blockage or airlock in the system.
So if I follow your method, would it clear the air from the system?
Thanks in advance.
Regards
Yes it normally works.
Only drain valve we have is on the boiler,which is situated on the ground floor under stairs, Valiant about 40 years old,no valve on rads,is it ok to drain system from boiler?
Yes it will be fine.
@@dereton33 will try it sometime,ours rads take forever to heat up downstairs, hasn't been flushed in over twenty years,thanks for your reply and helpful videos.
If the combi is the highest point in the system can it get air stuck inside, and if so how would you go about shifting it?
No they have a built in auto air vent.
Hi there, I have a town house, standard boiler on ground floor and hot water tank, pump, motorised valves for two zones 1.heating 2.hot water and pressurisation tank on top floor, I'm getting no heating on ground floor, two rads have heat at the lockshield but no heat in the rad middle floor but top floor is red hot. I replaced the pump thinking it could of gone but I'm getting the same issue, im feeling I have an airlock in the return between middle floor and top or a block, what are your thoughts
System just needs balancing.
@@dereton33 OK so how do I balance a system the feeds from a common pool, top floor I have done a quarter turn and they still red hot, middle floor and ground floor (each rad is a drop from middle Floor) I turned all ground floor full and middle floor half turn. I think my real question here as I watched your vid on balancing is how do I know what is my sequence in the rads how do I find this out
Air in combi boiler can be heard. What do I turn off and undo to remove the air pls is it just turn boiler off or lower pressure too before opening the drain valve
Combi boilers have a built in air valve. Check it is not stuck shut.
Can you show video how to back feed mains to get rid of airlock from drain cock.
Tried various methods unable to get rid of airlock.
Rads on top are warmish downstairs closed can hear air around the system.
Have you had your system cleaned in the last 5 years? If not it may be sludge in the system not air.
@dereton33 yeah was cleaned 5 years ago probably right yes. If air keeps building in system whats best way to release it.
Hi do you leave CH air vents and locks shield an try all open when flushing and only close when filling?
Trv,s
Leav them open while draining but not when flushing.
It’s not just the air, it’s also gunk that can do the same, changed the radiator in a bedroom and now we can’t bleed any radiator without the boiler cutting out!!! Nightmare
Heating systems, a right nightmare sometimes.
@@dereton33 It really is Al. Is it ever in your expert view a good idea to swap it all out with new electric wall heaters, and an electric water heater under the kitchen sink in a small 2 bed flat? Cheers
Hi ya...my system keeps filling with air. Was perfectly fine until the pump was changed. Had my yearly gas check a leak was noticed close to the pump and divert valve was stuck. The valve was changed and at the same time leak fixed and he changed the pump that was working fine. Since then the pump keeps getting airlocks. The past 6 weeks every few days I'm having to call the landlord to get gasman out again...to released the air.What could be causing it?
The pump is new so spinning faster than your old worn out one, so try turning the pump speed down a notch.
@@dereton33 thank you...just waiting for gasman still...so hopefully he will sort it...
I'm getting banging in my pipes when the heating comes on could this be a reason all my radiators run hot no cold spots
Err no.
@@dereton33 ok any ideas as to why maybe thank you
👍👍AL 💯💯💯 You are certainly not picasso 😵😵😵😵😂😂😂😂
I was a complete failure in the art class Paul, ha ha. The strange thing is that my daughter is an artist and runs her own gallery in Teignmouth.
@@dereton33meet me down the ale house 🍻🍻🍻🍺🍺🍺 we can be a pair of piss artists 😂😂😂😂
The dreaded airlock 😬
Dont we just hate them PB.
@@dereton33 if I'm working on a system that is notorious for bad airlocks I leave the drain hose on and fill the system up backwards from the mains....only recommend for the professional plumber though.
@@pb9926 good idea just out of interest when do you know when to stop filling?
@@kennethhogan9115 just have the mains ticking over Kenneth and start venting the radiators - downstairs then up, even if you left the mains on too long it would just go out of the F&E tank overflow so nothing to fear .
@@pb9926 Good idea do you do that often? I usually leave the drain off open for a food 10 mins when filling open vented systems and then vent radiators don't usually have too much bother
I have combi boiler so no 3 way valve
Yes you do it is inside the boiler case