Pedant mode engaged. A hydrosplit would be when the outdoor unit does not have it's own circulation pump. This system is not operating in that way. Your Cosy 6 is a Monobloc heat pump with a circulation pump inside it which has now been hydraulically separated from the heating circuit by a buffer tank. By knowing the metre head of the internal circulation pump in the cosy 6, they could have easily calculated if they had enough power to overcome the pipework resistance and achieve the correct flow rates to satisfy the heat demand of the property as well as keeping the Cosy 6 compressor and heat exchangers in the efficiency window. Calculating the external pipework is obviously a doddle, but even the plastic microbore should be straightforward to estimate. It does seem a bit of a failure that they couldn't/didn't calculate this before hand, but fair play to them for resolving the issue with hydraulic separation as most heat pump installers would do on plastic microbore with any heat pump, not just the Cosy 6. Interested in the COP but my predictions as I've repeated on my channel are that it will be fairly low. If it breaks 4 then I need to eat my hat live on my channel I guess. Thanks for sharing. The Cosy 6 is something I'm willing on as I do like to see vertical integration as I know how this can massively benefit widescale rollouts.
You'll need to start eating soon then - I have 4.13 and my install is earlier than this one :-) (Octopus also refitted my cylinder as, like yours, it was 180 and needed to be bigger).
Physics dictates that lower flow temperature improves heat pump COP, however the amount of heat that radiators can dissipate reduces with the flow temperature. When you reduced the minimum flow temperature the amount of heat the radiators were able to emit was less than the minimum modulation of the cosy 6 (probably about 2.5kW) which caused the cosy 6 to cycle on-off which reduced the COP. Generally the min flow temperature shouldn't be much more than about 10C lower than the design temperature e.g 30C for a 40C design or 40C for a 50C design, but this will vary depending on the amount and size of emitters. This spreadsheet can help with this calculation: ruclips.net/video/r7DJMJGQJUc/видео.htmlsi=a-xU8BxTJRfNRxq5. Agree that Octopus should use software and AI to determine this automatically.
They removed ability to change flow temperature settings so hopefully 🤞 my emails and this video means that’s what they plan to finally do now they have more cosy6 in the field!
I was just about to ask the same question. We got our Cosy 6 just over a week ago. 8m primary run outside, probably 22m total. A volumiser fitted from the start as we have 10mm microbore. SCOP so far is 3.1, which is slightly disappointing. Octopus are sending out an engineer to check everything. The installation team were superb. Once we have our solar and battery in a week, the SCOP will be less important...
Good info. Did you purchase any external fascias from somewhere or is that how octopus lagged the pipes? Finding it hard to find where to buy something for mine
I paid extra for it be in casing and they lagged that inside the case I knew the casing had to screw in the wall for the back end and couldn't be done easily after so opted for it to be done same time. 1 trick you can try is buying drain pipes and slit it one side
@ didn’t realise you could pay them extra for the job. Yeah I was thinking the same with the drain pipes. Will probably attach the corner sections to the wall and slot some together.
Interesting video as always Nick. I’ve just got a quote & awaiting a heat loss survey, not sure which ASHP they have included for ? With regards to the flow temperature I thought the weather compensation adjusted this depending on the outside temperature ?
It sounds like they didn't calculate the pressure loss of your pipe work. The pump couldn't shift the required power at low flow temperature due to the pressure loss of the pipe work. Since it could only output a small amount of power it cycled and you lost efficiency. This is not because low flow temperatures are inefficient. It's because low flow temperatures require higher flow rates which require suitably sized pipes. Please correct me if I'm wrong.
You've had some snarky comments but I appreciate you providing your empirical insights! If you've tried a low temperature to get a good CoP and it hasn't worked then fair enough!
I suspect most are upset heating fitters, octopus fitting heat pumps cheap upset them rather than concentrating on there core business they try to spend there time criticising others
@@Chris-hy6jy the grant that supports heat pump installations is a good way for the UK to meet its emissions targets. We aren't going to be able to keep burning gas forever.
@@Biggest-dh1vr Agreed, in real terms it’s no more or no less than when the local governments threw shed loads of cash at installing ‘natural gas’ central heating systems for all in the 70/80’s. That would’ve been even more disruptive as well for installation than heat pumps.
I'm looking into heat pump installation (ASHP+HWC) After watching several Heat Geek videos I was focusing on SCOP (maybe too much). In the end we decided to go with Octopus, as they provide the best value for money. I did some calculations and for my 3 bed semi (10,657kWh annual demand for heating and hot water) the difference between SCOP of 3.4 MCS minimum, and 4.5 (very optimistic) translates to £170 saving per year. As mentioned in previous comments Octopus is the best value for money for ASHP install (currently). If I were to go with well know independent install it will cost me an extra £3-£4k and will take around 17-20 years to pay it back. I'm sure someone like Heat Geek can design and Install more bespoke, and refined system than Octopus, but It is unlikely I will be in my current property in 2040 :-). I appreciate it, that for larger properties, payback will be sooner, but 3 bed semi , is fairly common house type in the UK.
You've made the right choice for your home. Do the maths first and you realise chasing that higher SCOP ends up costing you way more in the long run. It will be the likes of Octopus who will roll this out to the masses for the same cost (or cheaper in a lot of cases) as a replacement gas boiler. That's when a HP becomes a no brainer.
@andrewharris3900 except that I need to replace my boiler. Well, option two is to wear a lot of jumpers and have an extra 200 quid, but I think ASHP will go further.
The easiest way to have avoided this issue would have been to install the heat pump in a sensible location. The correct term is "Buffer Tank" it is NOT a "Multi Split" nor is it a "Low Loss Header". You have a responsibility as a content creator to provide accurate information on this topic. By doing this and adding an additional pump you will now be experiencing Hydraulic Distortion - this is the difference in flow between the various circuits and the 2 pumps.
Looking at your pipe run it is quite staggering. Mine, using a wall hanging unit means I can use a pipe run of around 4 feet. Intuitively that must be better. My initial COP was poor but that was before I balanced all my radiators. Doing that I currently get 3.2 (averaged with heating and HW) in recent days. Not outstanding but maybe with small changes this can be improved and this is on a microbore system. Getting all the rooms to the same temperature with only 1 zone does make a huge difference.
Bit disappointed you didnt share the COP before and after the changes. Would have been nice to see what you consider 'Awful' and how much its improved. Appreciate its early days but any data is better than no data. :)
Are you saying that the volumiser is now working as a Heat Store, where the radiator circulation pump pulls heat from it (in the form of heated water)?
Its bumped as a buffer 4 port. We have 1 side connected in a loop to heat pump and the other side looped to home supply with a small pump. The idea is this works and stops frictional resistance in my circuit
What have you got your flow temperature set to now octopus set mine to 37-57 and it was running so noisily outside and using loads of electric. Changed it to 35-45 and seeing a big improvement
We have microbore and a long run also , the headers tank was installed at the same time on our Cost 6 , so fortunately haven’t had any of your issues with cop. I did notice on the Cosy app though that they’ve taken away the flow temperature options on the Settings as of last week.
Until they decide not to. Without some 'lifetime contract' I'm afraid you are at the whim of Octopus to stick to their promise of looking after it. I'm sure they will, they'll just charge you for it instead, if not in a subscription, then in the annual servicing. I'll stick to something supplier agnostic that can be serviced by many of the competent engineers locally.
@ heat pump designs are pretty much basic same internally nothing hard but they supply install and maintenance manual with install so anyone could service it
Wow, what a failing on Octopus' part! This installation seems to go against a number of the essentials that Heat Geek say make up a good system! e.g. should not have a buffer/LLH/hydraulic separation, but pipe run too long, flow temps too low (lower IS better but the Cosy 6 seems different and possibly not a good thing!), and so on. And why did you end up with a 6KW HP when you say your heat loss is less than 4? That's more than 50% oversized even for the coldest day in the year and will obviously cause cycling and be less efficient. There are 4 and 5KW HPs available, Octopus even fit a Daikin 5KW themselves (unless they have just stopped?) With microbore (especially plastic which is worse as it has inserts that further restrict the flow) combined with that long run, Octopus should have known that hydraulic separation would be required to keep the HP happy. If your pipes are 12mm then you would have been better off with a shorter run and no hydraulic separation. Having the buffer is a significant hit on efficiency, as is higher flow temps - don't let them tell you otherwise - its just maybe the that Cosy 6 can't cope like some other HPs can. So you have ended up making less efficient changes to get the efficiency higher! Meaning a different system may (in theory) have given a better COP/SCOP. We need to see your number to make final judgement. I would love to see the Cosy 6 work well but it was over hyped and always set out to be a comprise that may well turn out to underperform.
Every install has problems that need to be solved, lessons learned at each install will improve following installs. They could have just installed it and walked away and left you to work it out, but they are trying to make it work it’s best for you. Keep the updates coming and remember every negative comment is engagement
Octopus are a big brand with an excellent reputation that they want to keep (unlike other mega-brands who don't seem to care). I think @EVNick is one of their test beds too?
Hi Nick, I had a heat pump survey and they estimated that I needed 12000 kWh for heating and hot water. My home only uses 6000 KWHs on gas. I think the surveys assumptions and heat loss calculations are miles out from actual consumption and heat loss. Why do they over spec heat pumps and consumption so much?
Mine is out by a factor of three… which is just insane. If I added the heat they suggest at a -4 outdoor temp the house would be well over 50 degrees C… That’s dangerously hot!
@@NicolasRaimo thanks Nick we are frugal here but I’d expect it to at least be equal to gas usage as a kWh is nearly 4 times more expensive when compared to gas.
@@alistairlambert3275 gas is 6.16p per kWh Electric 24p so you only need a cop of 3.5 to be price parity however octopus have deals for EV customers and heat pump customers plus loads of incentives for free power hours. I have 7p offpeak electric for example
Golly from the replies looks like you got to have a degree in physics to get one to work. Least i know now one is not suitable for my minbore system so thanks for the video
Did you get performance data for Cosy 6 ...... How many Kw it delivers at -2c or how low it can modulate down to at 10C .???? If your rads are set up to give out 6Kw at 50c flow , then at 30c flow they will only give 1.5Kw ish .. so If you know the minium output you can set the flow temp accordingly ... ( Vaillant 5Kw graph shows at 35c flow 10c it can't get below 2.3Kw & has a cop of 4.5 to 5 ish ) ..
I don’t seem to be able to change my flow temperature of my cosy 6 any more. When I go to the settings i only see the option to update wi-fi network. Maybe this is an intentional app update by octopus to stop us tweaking
On you huge pipe run, did they use ready insulated pipe, or clip the pipe on the wall then insulate it? Your trunking doesn't look big enough to fit the correct insulation on the pipes, but that could be the poor picture quantity on my phone! I would think 28 or maybe 32mm pipe with the required 15mm insulation gives about 60mm diameter, plus the trunking, so it should be at least 65mm off the wall. Clips mounted to the wall should also be over the insulation to avoid heat soaking into the brickwork. Is yours close to that?
People get so bogged down with efficiencies but go quiet when you ask them about the cost of getting that extra efficiency. The proof of the pudding is the OVERALL COST (install cost + operating cost) over a 15-20 year period. The independents can never compete with the likes of Octopus and BG on install cost, so getting an extra 0.5 SCOP with an independent, but having to pay twice the install cost to get the extra 0.5 SCOP is not always the answer. I personally like what Octopus are doing with the Cosy 6 and I like the brave design, so I'm interested in seeing your results once you have had a good winter to gather some real data and running costs. Stick with it as I suspect the results may be better than a lot of doubters are expecting.
100% when I did the math on using independents the payback added 10-15 years on to cost, If the heat pump broke in 12-15 years then I'd like to think that technology improvements in efficiency would of took place and if the heat pump last the full 15 years I just broke even so would need it to last another 5 years more to save me money time you add in the interest on that money i'd of earnt in the bank or not borrowing it.
Completely agree, I got a heat pump plus solar and battery installation for the same money as a guaranteed cop system, the battery and solar is a far better deal than the slightly higher cop considering the system can easily do 8-10 hours on battery alone (at 5p/kWh)
Or you can DIY like Glyn above and get something which is both very efficient and very cost-effective. And there are installers out there who can do you a decent system for about the same as the grant so you pay very little.
@@NicolasRaimo Conga in Ipswich have been doing installs which were 1-2 grand over the old 5 grand grant, so 6 or 7 grand total - i.e free with new grant. Obviously more if you want fancy stuff like UFH, and new hot water tanks put the price up. But HP installs don't have to cost a fortune - they just have to be designed properly to size. And yes Glyn is a smart chap but there is nothing in Glyn's install that most competent DIYers with a bit of plumbing experience couldn't do. It's not rocket science.
Big mistake fitting the heat pump so far away, and now a low loss header to make things worse. If the microbore was a problem then change it. Compromised to the point of failure. First principles. Great example of what not to do.
Don't be silly. Repiping the entire house would of cost a fortune making the heat pump install much more expensive and taking a stupid time to pay back first principles don't apply to retro fit, if it was first fit yes I agree.
@@NicolasRaimo You probably mentioned it in an earlier video but why not install it at the start of that pipe run eg near the front of the house rather than near the garage? Was it noise?
It's good that Octopus have fixed this but, a better installer would have got it right the first time. There was no way the pump in the Cosy6 was going to cope with the very long external run and microbore. Not enough pump head. You probably would have been better off with a hydro split system rather than a monobloc, due to the long external distance. Again, Octopus don't do this. They're cheap for a reason.
Lower is better, if your system is designed to deliver the heat at that temperature. Eg properly sized pipe work. It's not the low flow temperature that was the issue but your pipe work. It's why they designed for 50c. Personally I'm getting my pipe work upgraded if I can to enable a low temperature system. I want a scop 4+ HP not a 3+ for obvious cost reasons
We've all been told that this particular system is designed to run at "high temperature" (as they put it) compared to conventional heat pumps. Interesting about the Microbore, is yours running 10mm pipes? Thanks for sharing
Very informative Nick. I signed the contract for the Cosy 6 on Friday. They’ve assured me once I’m passed to the design team your referral code will be used. My run from cosy to 6 to the cylinder is quite short, I also do have microbore, so hopefully achieve a decent COP. Looking forward to the install.
@@davidgates3498 how many people live in your house David? I believe they provision for approx 45 litres per person per day when calculating the tank size. I have a 4 bed house and will be having a 210L tank installed.
... to be honest you need to be looking at the settings, i.e. the heat flux = flow rate + leaving water temp. as a starter. Urban Plumber has just released two videos today, which demonstrate the way to go???
@ I was thinking about the user, not your videos. I am finding it fascinating how a heat pump works. People are used to the radiators throwing out heat, yet the heat pump keeps them luke warm yet the house is warm.
@@bazcurtis178 I mean the user data will come my heat pump one of the first installs the app has had 2 large changes since September and data will come
This is why I'm going to pay extra for. heat geek. The designer should have known the pump wouldn't have been enough based upon the survey. I'm assuming they fitted the extra pump for free?
@@NicolasRaimo was referring more to the design stage oversight. You always pay for quality at some point. These are the kind of things the MSM jump on in an effort to slow the shift. A shame as I'm a happy Octopus customer but these HP installs seems almost worryingly cheap.
@@NicolasRaimo Yes but they are installing at a loss with time insentivised teams. This can bring questionable systems. Does Octopus provide annual servicing? If not you my have to try and find a plumber willing to fiddle/fix with your system and how that turns out could be interesting.
@@mbak7801 they offer a very competitive service and warranty package. I'm just not convinced that they are yet up to standard. You get what you pay for it.
I really don’t like the idea that Octopus have access to the data but not the customer, another good reason why I wouldn’t want Octopus to install my system now.
The most worrying thing about this install is Octopus thought they could run the whole thing off the Cosy pump with the massive primary run and then onto microbore, and also that they didnt have a real design temp so Nic decided he'd lower it himself to a value that clearly meant microbore would never deliver the required heat. A proper installer would have calculated this all properly from day one and not needed to fiddle with it so extensively. Seems a bit hit and hope. Still think it should have OEM on it, so we can all see the numbers openly. If Octopus believed this was a good solution they'd have no problem sticking it on OEM (like they have for some of their Daikin installs)
From my experience, it seems Octopus is trying everything possible to make sure that customers won't stick the OEM to the Cosy6. They'll try everything to discourage you if you bring up the OEM in any of your conversations.
@NicolasRaimo was referring more to the design oversight. Whilst they are a fair bit cheaper you are straight away having issues. I haven't yet gotten into an in depth like for like comparison, but I expect the warranty/guarantee will be longer on HG products. Their scops are consistently very good!
@@Chris-hy6jy true, seems like he lives in a fairly new house so not such an obvious motivation/saving. I think ours has got a few years left so expect we'll change to HP when it gives up
Slowly the realisation is setting in that he should have just left the gas boiler where it was, paid ZERO pounds to Octopus and stayed nice a warm this winter 😉
@NicolasRaimo wait till it's sub zero outside and we'll see. I'm not having a go mate, I just wouldn't have gone down that route, that's all. Not in your particular house with that particular set of circumstances.
![Noob To Max With DRAGON REWORK In Blox Fruits [FULL MOVIE]](http://i.ytimg.com/vi/LnBMOinoOvA/mqdefault.jpg)
Using Octopus Energy Services (Heat Pumps) then you can get £100 off when you split £200 with me Use my unique referral code: 87680
Hi Nick where do you input the code , could you pop a link here please m
@ just give that code to your ocotpus advisor and they will knock it off quote
Pedant mode engaged.
A hydrosplit would be when the outdoor unit does not have it's own circulation pump.
This system is not operating in that way.
Your Cosy 6 is a Monobloc heat pump with a circulation pump inside it which has now been hydraulically separated from the heating circuit by a buffer tank.
By knowing the metre head of the internal circulation pump in the cosy 6, they could have easily calculated if they had enough power to overcome the pipework resistance and achieve the correct flow rates to satisfy the heat demand of the property as well as keeping the Cosy 6 compressor and heat exchangers in the efficiency window.
Calculating the external pipework is obviously a doddle, but even the plastic microbore should be straightforward to estimate.
It does seem a bit of a failure that they couldn't/didn't calculate this before hand, but fair play to them for resolving the issue with hydraulic separation as most heat pump installers would do on plastic microbore with any heat pump, not just the Cosy 6.
Interested in the COP but my predictions as I've repeated on my channel are that it will be fairly low. If it breaks 4 then I need to eat my hat live on my channel I guess.
Thanks for sharing. The Cosy 6 is something I'm willing on as I do like to see vertical integration as I know how this can massively benefit widescale rollouts.
"If it breaks 4 then I need to eat my hat live on my channel I guess."
======
Noted 🙂
You'll need to start eating soon then - I have 4.13 and my install is earlier than this one :-) (Octopus also refitted my cylinder as, like yours, it was 180 and needed to be bigger).
Whats your hat made of and how good is your health care?
How come no higher than 4?
@@wreckguru You'll almost certainly dip below 4 by the time winter is over then, so no need for UDF to get his hat out just yet.
Physics dictates that lower flow temperature improves heat pump COP, however the amount of heat that radiators can dissipate reduces with the flow temperature. When you reduced the minimum flow temperature the amount of heat the radiators were able to emit was less than the minimum modulation of the cosy 6 (probably about 2.5kW) which caused the cosy 6 to cycle on-off which reduced the COP. Generally the min flow temperature shouldn't be much more than about 10C lower than the design temperature e.g 30C for a 40C design or 40C for a 50C design, but this will vary depending on the amount and size of emitters. This spreadsheet can help with this calculation: ruclips.net/video/r7DJMJGQJUc/видео.htmlsi=a-xU8BxTJRfNRxq5. Agree that Octopus should use software and AI to determine this automatically.
They removed ability to change flow temperature settings so hopefully 🤞 my emails and this video means that’s what they plan to finally do now they have more cosy6 in the field!
I've just had a Cosy 6 installed and I can't see anything in the app settings to change the flow temperature am I not seeing something?
They took it out ;)
Thanks, I thought that might be the case.
I was just about to ask the same question.
We got our Cosy 6 just over a week ago. 8m primary run outside, probably 22m total. A volumiser fitted from the start as we have 10mm microbore.
SCOP so far is 3.1, which is slightly disappointing.
Octopus are sending out an engineer to check everything.
The installation team were superb.
Once we have our solar and battery in a week, the SCOP will be less important...
Good info. Did you purchase any external fascias from somewhere or is that how octopus lagged the pipes? Finding it hard to find where to buy something for mine
I paid extra for it be in casing and they lagged that inside the case I knew the casing had to screw in the wall for the back end and couldn't be done easily after so opted for it to be done same time. 1 trick you can try is buying drain pipes and slit it one side
@ didn’t realise you could pay them extra for the job. Yeah I was thinking the same with the drain pipes. Will probably attach the corner sections to the wall and slot some together.
Interesting video as always Nick. I’ve just got a quote & awaiting a heat loss survey, not sure which ASHP they have included for ? With regards to the flow temperature I thought the weather compensation adjusted this depending on the outside temperature ?
Weather comp works within a range that customers could change but octopus locked it out since this video and engineers and octopus will set
Whenever I see the cosy6 in videos my immediate thoughts are it looks like a McDonalds car park bin 👀
It’s not for everyone I get that but I prefer it to other units
@ I mean the technology does seem sound, just not sure I feel the aesthetics, suppose it needs to be hidden out of sight.
A Pacific issue or a specific issue? :)
It sounds like they didn't calculate the pressure loss of your pipe work. The pump couldn't shift the required power at low flow temperature due to the pressure loss of the pipe work. Since it could only output a small amount of power it cycled and you lost efficiency. This is not because low flow temperatures are inefficient. It's because low flow temperatures require higher flow rates which require suitably sized pipes. Please correct me if I'm wrong.
You've had some snarky comments but I appreciate you providing your empirical insights! If you've tried a low temperature to get a good CoP and it hasn't worked then fair enough!
I suspect most are upset heating fitters, octopus fitting heat pumps cheap upset them rather than concentrating on there core business they try to spend there time criticising others
@@NicolasRaimo Not cheap, just paid for by the tax payer.
@@Chris-hy6jy the grant that supports heat pump installations is a good way for the UK to meet its emissions targets. We aren't going to be able to keep burning gas forever.
@@Biggest-dh1vr a complete and utter waste of time when you compare the UK's emissions with countries like China, India and the US.
@@Biggest-dh1vr
Agreed, in real terms it’s no more or no less than when the local governments threw shed loads of cash at installing ‘natural gas’ central heating systems for all in the 70/80’s.
That would’ve been even more disruptive as well for installation than heat pumps.
I'm looking into heat pump installation (ASHP+HWC) After watching several Heat Geek videos I was focusing on SCOP (maybe too much). In the end we decided to go with Octopus, as they provide the best value for money. I did some calculations and for my 3 bed semi (10,657kWh annual demand for heating and hot water) the difference between SCOP of 3.4 MCS minimum, and 4.5 (very optimistic) translates to £170 saving per year. As mentioned in previous comments Octopus is the best value for money for ASHP install (currently). If I were to go with well know independent install it will cost me an extra £3-£4k and will take around 17-20 years to pay it back. I'm sure someone like Heat Geek can design and Install more bespoke, and refined system than Octopus, but It is unlikely I will be in my current property in 2040 :-). I appreciate it, that for larger properties, payback will be sooner, but 3 bed semi , is fairly common house type in the UK.
100% my findings also, ps don’t forget to add my refferal code for extra £100 off
You've made the right choice for your home. Do the maths first and you realise chasing that higher SCOP ends up costing you way more in the long run. It will be the likes of Octopus who will roll this out to the masses for the same cost (or cheaper in a lot of cases) as a replacement gas boiler. That's when a HP becomes a no brainer.
Just put your £4k in a savings account, that’s £208 per year currently. It’s a better investment than a heat pump.
@@andrewharris3900 boiler replacement same price so not really plus it’s not all about cost
@andrewharris3900 except that I need to replace my boiler. Well, option two is to wear a lot of jumpers and have an extra 200 quid, but I think ASHP will go further.
The easiest way to have avoided this issue would have been to install the heat pump in a sensible location.
The correct term is "Buffer Tank" it is NOT a "Multi Split" nor is it a "Low Loss Header".
You have a responsibility as a content creator to provide accurate information on this topic.
By doing this and adding an additional pump you will now be experiencing Hydraulic Distortion - this is the difference in flow between the various circuits and the 2 pumps.
A suggesting you check what a low loss header is www.heatgeek.com/low-loss-headers/
Looking at your pipe run it is quite staggering. Mine, using a wall hanging unit means I can use a pipe run of around 4 feet. Intuitively that must be better. My initial COP was poor but that was before I balanced all my radiators. Doing that I currently get 3.2 (averaged with heating and HW) in recent days. Not outstanding but maybe with small changes this can be improved and this is on a microbore system. Getting all the rooms to the same temperature with only 1 zone does make a huge difference.
Bit disappointed you didnt share the COP before and after the changes. Would have been nice to see what you consider 'Awful' and how much its improved. Appreciate its early days but any data is better than no data. :)
It was awful based on the outside temperature but that isn't comparable to the temperature a month later....
Are you saying that the volumiser is now working as a Heat Store, where the radiator circulation pump pulls heat from it (in the form of heated water)?
Its bumped as a buffer 4 port. We have 1 side connected in a loop to heat pump and the other side looped to home supply with a small pump. The idea is this works and stops frictional resistance in my circuit
What have you got your flow temperature set to now octopus set mine to 37-57 and it was running so noisily outside and using loads of electric. Changed it to 35-45 and seeing a big improvement
We have microbore and a long run also , the headers tank was installed at the same time on our Cost 6 , so fortunately haven’t had any of your issues with cop. I did notice on the Cosy app though that they’ve taken away the flow temperature options on the Settings as of last week.
I’ve been in communication with octopus and they have staff as RUclips members and patrons seeing this content early
I noticed the flow temp settings had been removed download a older version of the app to get them back
Wonder where the data goes if move away from octopus?
Octopus will still look after the heat pump even if you aren’t an energy customer
@JohnR31415 didn't know that. For free??
yes
Until they decide not to. Without some 'lifetime contract' I'm afraid you are at the whim of Octopus to stick to their promise of looking after it. I'm sure they will, they'll just charge you for it instead, if not in a subscription, then in the annual servicing. I'll stick to something supplier agnostic that can be serviced by many of the competent engineers locally.
@ heat pump designs are pretty much basic same internally nothing hard but they supply install and maintenance manual with install so anyone could service it
Wow, what a failing on Octopus' part! This installation seems to go against a number of the essentials that Heat Geek say make up a good system! e.g. should not have a buffer/LLH/hydraulic separation, but pipe run too long, flow temps too low (lower IS better but the Cosy 6 seems different and possibly not a good thing!), and so on.
And why did you end up with a 6KW HP when you say your heat loss is less than 4? That's more than 50% oversized even for the coldest day in the year and will obviously cause cycling and be less efficient. There are 4 and 5KW HPs available, Octopus even fit a Daikin 5KW themselves (unless they have just stopped?)
With microbore (especially plastic which is worse as it has inserts that further restrict the flow) combined with that long run, Octopus should have known that hydraulic separation would be required to keep the HP happy. If your pipes are 12mm then you would have been better off with a shorter run and no hydraulic separation. Having the buffer is a significant hit on efficiency, as is higher flow temps - don't let them tell you otherwise - its just maybe the that Cosy 6 can't cope like some other HPs can.
So you have ended up making less efficient changes to get the efficiency higher! Meaning a different system may (in theory) have given a better COP/SCOP. We need to see your number to make final judgement.
I would love to see the Cosy 6 work well but it was over hyped and always set out to be a comprise that may well turn out to underperform.
Every install has problems that need to be solved, lessons learned at each install will improve following installs. They could have just installed it and walked away and left you to work it out, but they are trying to make it work it’s best for you. Keep the updates coming and remember every negative comment is engagement
Octopus are a big brand with an excellent reputation that they want to keep (unlike other mega-brands who don't seem to care). I think @EVNick is one of their test beds too?
Hi Nick, I had a heat pump survey and they estimated that I needed 12000 kWh for heating and hot water. My home only uses 6000 KWHs on gas. I think the surveys assumptions and heat loss calculations are miles out from actual consumption and heat loss. Why do they over spec heat pumps and consumption so much?
They us MCs surgery and calculations but also you might be running it colder than next person who moved in would like it
Mine is out by a factor of three… which is just insane. If I added the heat they suggest at a -4 outdoor temp the house would be well over 50 degrees C…
That’s dangerously hot!
@ that’s why we have thermostats
@@NicolasRaimo thanks Nick we are frugal here but I’d expect it to at least be equal to gas usage as a kWh is nearly 4 times more expensive when compared to gas.
@@alistairlambert3275 gas is 6.16p per kWh
Electric 24p so you only need a cop of 3.5 to be price parity however octopus have deals for EV customers and heat pump customers plus loads of incentives for free power hours. I have 7p offpeak electric for example
Golly from the replies looks like you got to have a degree in physics to get one to work. Least i know now one is not suitable for my minbore system so thanks for the video
If it’s 10mm it be fine but 8 will need a repipe to use octopus but some Indy installs may do it
@NicolasRaimo no it's not 8mm by looks of it.
Did you get performance data for Cosy 6 ...... How many Kw it delivers at -2c or how low it can modulate down to at 10C .???? If your rads are set up to give out 6Kw at 50c flow , then at 30c flow they will only give 1.5Kw ish .. so If you know the minium output you can set the flow temp accordingly ... ( Vaillant 5Kw graph shows at 35c flow 10c it can't get below 2.3Kw & has a cop of 4.5 to 5 ish ) ..
I don’t seem to be able to change my flow temperature of my cosy 6 any more. When I go to the settings i only see the option to update wi-fi network. Maybe this is an intentional app update by octopus to stop us tweaking
Mine is the same I've only had it a fortnight I had it in the first week.
On you huge pipe run, did they use ready insulated pipe, or clip the pipe on the wall then insulate it? Your trunking doesn't look big enough to fit the correct insulation on the pipes, but that could be the poor picture quantity on my phone! I would think 28 or maybe 32mm pipe with the required 15mm insulation gives about 60mm diameter, plus the trunking, so it should be at least 65mm off the wall. Clips mounted to the wall should also be over the insulation to avoid heat soaking into the brickwork. Is yours close to that?
People get so bogged down with efficiencies but go quiet when you ask them about the cost of getting that extra efficiency. The proof of the pudding is the OVERALL COST (install cost + operating cost) over a 15-20 year period. The independents can never compete with the likes of Octopus and BG on install cost, so getting an extra 0.5 SCOP with an independent, but having to pay twice the install cost to get the extra 0.5 SCOP is not always the answer. I personally like what Octopus are doing with the Cosy 6 and I like the brave design, so I'm interested in seeing your results once you have had a good winter to gather some real data and running costs. Stick with it as I suspect the results may be better than a lot of doubters are expecting.
100% when I did the math on using independents the payback added 10-15 years on to cost, If the heat pump broke in 12-15 years then I'd like to think that technology improvements in efficiency would of took place and if the heat pump last the full 15 years I just broke even so would need it to last another 5 years more to save me money time you add in the interest on that money i'd of earnt in the bank or not borrowing it.
Completely agree, I got a heat pump plus solar and battery installation for the same money as a guaranteed cop system, the battery and solar is a far better deal than the slightly higher cop considering the system can easily do 8-10 hours on battery alone (at 5p/kWh)
Or you can DIY like Glyn above and get something which is both very efficient and very cost-effective. And there are installers out there who can do you a decent system for about the same as the grant so you pay very little.
@ octopus only people I seen this cheap everyone else wanting 7k over grant! Glynn not your typical diy he is a super smart engineer and a top bloke
@@NicolasRaimo Conga in Ipswich have been doing installs which were 1-2 grand over the old 5 grand grant, so 6 or 7 grand total - i.e free with new grant. Obviously more if you want fancy stuff like UFH, and new hot water tanks put the price up. But HP installs don't have to cost a fortune - they just have to be designed properly to size.
And yes Glyn is a smart chap but there is nothing in Glyn's install that most competent DIYers with a bit of plumbing experience couldn't do. It's not rocket science.
Big mistake fitting the heat pump so far away, and now a low loss header to make things worse. If the microbore was a problem then change it. Compromised to the point of failure. First principles. Great example of what not to do.
Don't be silly. Repiping the entire house would of cost a fortune making the heat pump install much more expensive and taking a stupid time to pay back first principles don't apply to retro fit, if it was first fit yes I agree.
@@NicolasRaimo You probably mentioned it in an earlier video but why not install it at the start of that pipe run eg near the front of the house rather than near the garage? Was it noise?
@ has to be 1 meter from boundary I wanted it right front of my home next to my bedroom window. It makes no noise
It's good that Octopus have fixed this but, a better installer would have got it right the first time. There was no way the pump in the Cosy6 was going to cope with the very long external run and microbore. Not enough pump head.
You probably would have been better off with a hydro split system rather than a monobloc, due to the long external distance. Again, Octopus don't do this. They're cheap for a reason.
Sorry to hear you have microbore mate.
Lower is better, if your system is designed to deliver the heat at that temperature. Eg properly sized pipe work.
It's not the low flow temperature that was the issue but your pipe work. It's why they designed for 50c.
Personally I'm getting my pipe work upgraded if I can to enable a low temperature system. I want a scop 4+ HP not a 3+ for obvious cost reasons
The price of a re pipe would far outweigh the cost savings also the up evil of having to repipe would of meant a no go from the other half
We've all been told that this particular system is designed to run at "high temperature" (as they put it) compared to conventional heat pumps. Interesting about the Microbore, is yours running 10mm pipes? Thanks for sharing
10mm plastic microbore
Very informative Nick. I signed the contract for the Cosy 6 on Friday. They’ve assured me once I’m passed to the design team your referral code will be used. My run from cosy to 6 to the cylinder is quite short, I also do have microbore, so hopefully achieve a decent COP. Looking forward to the install.
Excellent! I’ll be putting out October members cop screenshot on 1st November!
@@NicolasRaimo look forward to seeing the stats 👌🏻
Thanks Nick. Sorry to hear about your issues. How big is your tank. I'm a bit worried that 180 is not enough for my install
@@davidgates3498 how many people live in your house David? I believe they provision for approx 45 litres per person per day when calculating the tank size. I have a 4 bed house and will be having a 210L tank installed.
@@liamhenning Thanks for that. 2 adults and 2 children, 6 & 10 years old.
cop 4 heating
cop 2.8 hot water
cop from install to 10-11-2024
Mediocre!
Let’s see how much the hydraulic separation will improve the COP
@@serraios1989
There will be one more pump to account for, and potential turbulence in the buffer tank, neither of which would be beneficial to COP.
@@_Dougaldog
Agreed. Not ideal, but should improve the COP
After seeing Urban Plumbers video of monster 24kW heat pump I need to get down to earth with a cosy6.
... to be honest you need to be looking at the settings, i.e. the heat flux = flow rate + leaving water temp. as a starter. Urban Plumber has just released two videos today, which demonstrate the way to go???
What a clart on man.
I used to have a flow temeratue setting on my cosy 6 app which suddenly disapeared
I am glad I have a Daikin and installed ESPAltherma. I can see a lot of data this way.
data will come its a new HP
@ I was thinking about the user, not your videos. I am finding it fascinating how a heat pump works. People are used to the radiators throwing out heat, yet the heat pump keeps them luke warm yet the house is warm.
@@bazcurtis178 I mean the user data will come my heat pump one of the first installs the app has had 2 large changes since September and data will come
This is why I'm going to pay extra for. heat geek. The designer should have known the pump wouldn't have been enough based upon the survey. I'm assuming they fitted the extra pump for free?
All work included yes, heat geek payback vs octopus price was miles apart
@@NicolasRaimo was referring more to the design stage oversight. You always pay for quality at some point. These are the kind of things the MSM jump on in an effort to slow the shift. A shame as I'm a happy Octopus customer but these HP installs seems almost worryingly cheap.
@@NicolasRaimo Yes but they are installing at a loss with time insentivised teams. This can bring questionable systems. Does Octopus provide annual servicing? If not you my have to try and find a plumber willing to fiddle/fix with your system and how that turns out could be interesting.
@@mbak7801 they offer a very competitive service and warranty package. I'm just not convinced that they are yet up to standard. You get what you pay for it.
@ they offer services yes
I’m afraid it looks ugly and cheap. It’s a no from me, I’ll take a conventional looking heat pump.
I really don’t like the idea that Octopus have access to the data but not the customer, another good reason why I wouldn’t want Octopus to install my system now.
Every single heat pump manufacture that has internet access has your data so thats a silly example
but not the customer 🤔
@ mate they did quote me, and now they are compensating me - long story short, they messed up big style.
@@jimmyc38 cosy6 just started being fitted for customer the data for customers is coming soon it’s a new product
@@jimmyc38 ?
God you seem to get some grief. Stick with it and thanks very much for posting your experience. Stay positive. Eddy
People hate change got the same nasty comments when I started doing electric cars back in 2015
The most worrying thing about this install is Octopus thought they could run the whole thing off the Cosy pump with the massive primary run and then onto microbore, and also that they didnt have a real design temp so Nic decided he'd lower it himself to a value that clearly meant microbore would never deliver the required heat. A proper installer would have calculated this all properly from day one and not needed to fiddle with it so extensively. Seems a bit hit and hope. Still think it should have OEM on it, so we can all see the numbers openly. If Octopus believed this was a good solution they'd have no problem sticking it on OEM (like they have for some of their Daikin installs)
From my experience, it seems Octopus is trying everything possible to make sure that customers won't stick the OEM to the Cosy6. They'll try everything to discourage you if you bring up the OEM in any of your conversations.
Think I will stick with my Worcester Bosch gas boiler for a while longer.
why
Sounds like you should have got a Heat Geek install 😉
At over 7k no thanks payback been far longer than life of heat pump
@NicolasRaimo was referring more to the design oversight. Whilst they are a fair bit cheaper you are straight away having issues. I haven't yet gotten into an in depth like for like comparison, but I expect the warranty/guarantee will be longer on HG products. Their scops are consistently very good!
Or just left the gas boiler where it was!
@@Chris-hy6jy true, seems like he lives in a fairly new house so not such an obvious motivation/saving. I think ours has got a few years left so expect we'll change to HP when it gives up
@@NicolasRaimo You don't install for payback. That is the wrong way of thinking. You install for comfort and usability.
Slag!
Slowly the realisation is setting in that he should have just left the gas boiler where it was, paid ZERO pounds to Octopus and stayed nice a warm this winter 😉
It’s nice and warm now and cheaper to run than my boiler
@NicolasRaimo wait till it's sub zero outside and we'll see. I'm not having a go mate, I just wouldn't have gone down that route, that's all. Not in your particular house with that particular set of circumstances.
@ heat pumps proven technology they work sub zero
@@NicolasRaimo I have two air to air units myself. They work in sub zero, just not as well and efficiency takes a dive.
@@Chris-hy6jy air to air isn’t as efficient thou… even as a cop of 3 this be cheaper to run than gas