Thanks for your update. I am so glad for you that you have finally found a resolution with the oil heating system… after 5 years

I just got the electricity bill for this month and it was £388.00  - 3/4 of that was the heat pump, which is just too expensive to operate. I know this because it is a cascade system.

I’ve been advised that a monobloc would work, but I would need to have new heating system pipes put in and that could mean lifting floorboards. The pipes from the heat pump have a dia of 25mm and these are reduced to 22mm into the pumps before being reduced further to 15mm. This means that the flow rate has to be increased substantially in order to successfully transport the volumes of heated water required to the radiators. In order for the system to work properly they should be all 22mm and not 15mm. So the Heatpump has to operate at higher temperatures and at higher flow rates - this uses energy which results in a COP of 1.3.

I continue to investigate supplemental systems and in the meantime I will contact the HIES governing body next week to begin to get some resolution for my system through that route.

Great to hear your news

@jet sorry to hear you are still struggling with your system. At one point in my complaint they advise me to have an additional 8 kw unit bolted on to my system,creating a cascade unit. The other way round to what you are being told. My ASHP system was designed to run at 55 degrees which the unit installed should have been able to run.My costings were given at that flow temp. My pump just couldn’t reach that flow temp when it was 0 degrees outside.

I don’t understand the ins and outs of pipe sizes but my system sounds to be similar to yours  28-22–15 at the rads.The oil boiler is set at its lowest setting of 55 degree flow ie the same as the design temp of the ASHP system and it works really well. Napit refused to send an independent engineer to look at my system so I will never know if the pipe sizes were anything to do with it or not. I suspect not and that it was just the ASHP that couldn’t deliver the require flow temp not even near. It is all so confusing to be honest and I don’t think that us as consumers should be the ones left to fight to have it put right. I paid for a system that would heat my property to 21 degrees with a running cost of 8250 kWh per years not between 13000 and 15000 kWh to heat my property to 16 degrees. ( sorry to rant). I am not suggesting oil to anyone one but my new system warms my houses easily and cost less to run and if it should break down there are about 10 local engineers that could fix it rather than 1. I really hope you find a solution to your issues soon , it is so stressful. Good luck. 

@tworivers I have a similar story to you. Left after 2 years with a heat pump that apparently wasn’t designed correctly so is undersized but as the company have gone into administration, we have no recourse as the warranty company are refusing to cover us due to some small print. If you’d be interested in joining forces to tell our stories and hopefully get some change in the industry to protect others in the future from unscrupulous installers, please get in contact. My local MP is willing to take this to government but I need around 20 people as a minimum with similar stories for him to do this. We’re about to go into our third winter with no means to warm our house apart from an apparently undersized heat pump which will cost a fortune to get the house to 12 degrees! I feel it’s time our voices are heard.

@fiona sorry to hear that, and I sympathise with you because there simply isn’t any effective recourse out for consumers with bodged installs. I’m currently looking at legal avenues for homeowners to follow which I feel is the only way forward to instill meaningful change.

If you’d like to get the ball rolling in the time being, please free to start a new post outlining your case and issues.

@fiona sorry to hear you are going through similar experience to me. 😡. I would be willing to tell my story if that helps. I can’t believe the governing bodies get away with treating people like this.In my instance I asked them on several occasions to send an independent engineer to inspect my system but they where more than happy for the installer to basically mark his own home work which left me and my family baffled. It seems installers pay these so called governing bodies for their accreditation which just seems so wrong on all fronts. 
Update on my new oil boiler system. My home kept warm to 20-21 degrees through winter no problem at all. Boiler set to 60 degrees ( the lowest setting possible) this proves that my install design temp of 55 degrees was actually right but the ASHP just wasn’t capable of 55 degrees.
Cost oil vs ASHP the average cost to keep my house between 12-😟17 degrees ( depending on outside temp)£3226 p/a vs 20 degrees with oil £1426. A saving of £1800 and a warm house and happy family.

@tworivers, did you remove the heat pump?

@editor yes it was replaced with an oil boiler September 2024 so its just be in for a year last month.

Posted by: @jet

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uses energy which results in a COP of 1.3.

That is scandalous.  Would you care to say something about house (size, construction) and system (make and model, buffer or no buffer, preplumbed cylinder or not, rads?, what flow temp are you operating at and is weather compensation enabled).  A properly designed system should achieve a scop of well over 3 and more like 4 ( or more if you have ufh.)

Posted by: @editor

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If you’d like to get the ball rolling in the time being, please free to start a new post outlining your case and issues.

@fiona I really encourage you to do this.  There are very probably things that can be done with little or no expenditure to improve the situation. 

If you tell us something about house (size, construction, very rough location) and system (make and model, buffer or no buffer, preplumbed cylinder or not, rads or underfloor, what flow temp are you operating at and is weather compensation enabled) maybe someone can suggest something.  If you don't know all the above say what you do know,

Posted by: @jet

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Posted by: @jet

uses energy which results in a COP of 1.3.

That is scandalous. 

I’m still waiting for the day we see an install running with a COP below 1 using more electricity than the heat it delivers. At that point, we’ve basically recreated a badly wired electric boiler. And honestly, with some of the cowboy installs out there, I wouldn’t be surprised if that day isn’t far off. 😮 

Posted by: @editor

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I’m still waiting for the day we see an install running with a COP below 1 using more electricity than the heat it delivers. At that point, we’ve basically recreated a badly wired electric boiler. And honestly, with some of the cowboy installs out there, I wouldn’t be surprised if that day isn’t far off.  

It's unbelievable isn't it the extent to which some people can mess up. 

As I have said before it's not confined to heat pumps either, I had a flat roof replaced by someone very credible who turned out to be a cowboy, resulting in flooding on boxing day.  The whole thing had to be stripped off and redone and I ended up paying twice.  As I write this I'm about to cross the Tay rail bridge.  The original collapsed in 1879, killing all 59 on board the train, at least in part due to dodgy builders and suspect design.  Nothing changes.

@editor I would be gobsmacked if you found a system performing at 1 or less, that would take some messing up. I went on to our systems today just to check the ones we monitor for customers and now we are at the beginning of the heating season and they are all between 4.1 and 4.6 so a good result for the beginning of the season, we do not install to chase the SCOPs as we are more of a tailored designer aiming at comfort and efficiency combined as we believe it the home owners system and it should be designed around what they would like rather than our toy to get credibility on the SCOP chasing.

All systems should be able to meet the required design temperature and a deg above if you choose in my opinion, this way it just a matter of control and settings.