Buying a house with an ASHP – what to look out for and what questions to ask?
Posted by: @derek-mWho is the manufacturer?
Mitsubishi
I observe that under Mitsubishi auto adaption that set back to 15C at night causes the HP to cease heating and runs in freeze stat until the next set point at 0600. When it was seriously cold recently, in the minus 10C area over night, it was waking up around 0500 hours to commence its days work regardless that the wireless room stat was not calling for heat.
Posted by: @abernytePosted by: @derek-mWho is the manufacturer?
Mitsubishi
I observe that under Mitsubishi auto adaption that set back to 15C at night causes the HP to cease heating and runs in freeze stat until the next set point at 0600. When it was seriously cold recently, in the minus 10C area over night, it was waking up around 0500 hours to commence its days work regardless that the wireless room stat was not calling for heat.
It would appear that auto adaptation was actually 'adapting' to the adverse weather condition. 😎 Well done Mitsubishi. 😀
Would you care to name your installer?
I would readily but the guy is seriously ill at present, hence the manufacturer service contract.
In reality, without monitoring equipment installed, it is very difficult to determine the actual, accurate performance of any heating system regardless of technology. Here is a link to a Linked in post, of a heating consultant finding out that his gas boiler is only 67% efficient after putting monitoring equipment on.
As a rule of thumb, if the heat pump system has a buffer tank, system separation, if you can see more than 1 pump, and there are third party thermostats, there is little chance that there will be any level of reasonable performance and there is a good possibility that the bills will be very high.
Director at Heacol | Expert Heat Pump Consultant | Book a one-to-one consultation for pre- and post-installation advice, troubleshooting and system optimisation.
@sapper117, I guess it comes down to people and their ‘experience’. We purchased our property from people that were used to buying and selling properties that they fixed up and sold, and they were less than truthful in their signed documents and forms.
When we raised this with our solicitor post purchase (having discovered the issues after moving in), the legal fees and claims process was very costly and not worth the financial effort.
I suspect it might be the same with a bodged heat pump. If you have the capital, it might be cheaper to fix and replace then to seek legal routes to get financial compensation.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
@editor I suspect you are right in England - up north we have to sign docs with legal answers and each sale has a week to check elec gas boilers etc which if the buyer is well briefed and carried out their due diligence then they will have an engineer in on day one. As a retired property manager I would organise this for clients buying a new property ( new to them) and never had a problem here.
If I were buying a place with tech I wasn't familiar with, I'd probably look for an expert to do an inspection. Surveyors are common for structural issues, electricians for electrical checks, boiler people for gas heating and I don't think heatpumps are much different. So I might pay somebody to visit and inspect - if I didn't know anyone, likely finding somebody who is certified by the manufacturer of this particular model to check it's installed correctly.
In this instance I probably wouldn't trust a 'gas safety certificate' or its heatpump equivalent (proof that it's been serviced recently) since we don't know if the person who recently serviced it knew what they were doing, unlike gas safety certs which are well understood. Evidence of servicing is good, like GasSafe or HETAS paperwork is - although heatpumps don't really need a lot of servicing so it wouldn't be a showstopper if it didn't exist.
If I were being picky I might also ask my inspector to do heatloss calcs and confirm the unit is correctly sized. It might be too large if additional insulation was added after it was installed.
Although I might be tempted to make sure there's some slack in the budget just in case it did need to be replaced - which should be cheaper than a full install since it's mainly the outdoor unit that would be changed.
@prunus the odds are the heat pump unit would be ok its the installation and heat calcs you would need checked as it seems that most of the problems emulate from failing here - and costs to make good could be larger than a new pump
- 22 Forums
- 2,055 Topics
- 44.8 K Posts
- 18 Online
- 3,289 Members
Join Us!
Trusted Installers
Struggling to find a reliable heat pump installer? A poor installation can lead to inefficiencies and high running costs. We now connect homeowners with top-rated installers who deliver quality work and excellent service.
✅ Verified, trusted & experienced installers
✅ Nationwide coverage expanding
✅ Special offers available
Latest Posts
-
Win a 6-panel PV courtesy of egg and Renewable Heating Hub
Our epic giveaway just went live! Want to win a 6-pan...
By Mars , 6 hours ago
-
RE: Yes, the "zoning with ASHP" topic again...
James, thanks again for your thoughtful and persistent ...
By HarryRea , 6 hours ago
-
RE: Getting the best out of a heat pump - is Homely a possible answer?
Isn't that the whole point of homely - it does that fun...
By Johnmo , 8 hours ago
-
RE: Is this normal? Click of the DHW returning to space heating
So the Lone Ranger returned today! Even though we thoro...
By Grantmethestrength , 9 hours ago
-
RE: How To Balance Radiators & the Role of the Lockshield Valve: A Homeowner's Guide
@jamespa So settings to date are as follows for now. ...
By Alfapat , 9 hours ago
-
RE: Vaillant & OVO partner up to offer Heat Pump Plus
Hopefully iv done the right thing today by signing up t...
By Westkent , 11 hours ago
-
RE: IVT Greenline high pressure switch and electrical cassette errors
Hi, are you able to see the delta between GT8 vs GT9 te...
By abbote , 12 hours ago
-
RE: Battery sizing - How low can you go!
My own experience with connecting four batteries to thr...
By Transparent , 18 hours ago
-
RE: Plate heat exchanger considerations
Work on 2-3 percent per degree. This is a reasonable e...
By JamesPa , 1 day ago
-
RE: Advice for ground source heat pump in new build with PV and batteries
The useful bit is the bit that specifies the heat loss ...
By JamesPa , 1 day ago
-
RE: Volumisers in Heat Pump Systems: Does Placement Matter?
You’re absolutely right that during defrost the refrige...
By Mars , 1 day ago
-
@editor thanks Mars that’s the same table I found in th...
By Gary , 1 day ago
-
RE: Tariff and charging strategy advice please
They haven't asked me to prove that I have an EV (I do)...
By JamesPa , 2 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
Took a while to find on the OFGEN site: ”The FIT sche...
By AgentGeorge , 2 days ago
-
RE: why solar diverters for HW instead of the heat pump?
For me there are few factors why you may want to heat w...
By Johnmo , 2 days ago
-
RE: Hydronic plinth heaters and ASHPs
@editor yes I think so. It will be a while until I get ...
By benson , 2 days ago
-
RE: Aira Heat Pump: Stylish Scandinavian Heating
I’m an Aira customer with a 6kW Outdoor Unit in a small...
By KevinPotts , 2 days ago
-
RE: Is your heat pump insured?
@richard24738 good to hear. I’ll also review them this ...
By Mars , 2 days ago
-
RE: Warm weather and heat pumps.
Just looked at my WC setting, it is programmed for 25 D...
By Johnmo , 2 days ago