Has anyone replaced an old ASHP with a new one?
@pressure sounds like a positive outcome and glad you’re happy with it so far. Keep us posted on your progress and whether running costs are better than with your old unit.
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
@pressure very interesting read - thanks for posting. A lot of us will have such decisions in coming years. Hopefully mine is still 10 years away.. LG installed 2020.
How did you decide on 9kw? Did you do heat loss calcs as if new install? Of use actual data from existing heat pump? Or??
Mine is currently 16kw which I think is probably about "right size" on paper but with the way we run with cooler bedrooms and some other rooms also cooler I suspect we could drop to something like 10 or 12 kw.
I don't know how much improvement there might be to COP over the years?
Listed Grade 2 building with large modern extension.
LG Therma V 16kw ASHP
Underfloor heating + Rads
8kw pv solar
3 x 8.2kw GivEnergy batteries
1 x GivEnergy Gen1 hybrid 5.0kw inverter
Manual changeover EPS
MG4 EV
I settled on 9 kw after:
1. Doing heat loss calcs using free online calculators to give me an idea of the likely requirement
2. the installer got a proper, detailed calculation done based on the house plans etc.
In the end the calcs said 8kw would work but the 9 kw model has a back up immersion heater, which recent experience indicated we definitely need!
I think the new system is more efficient but I won’t have the data to demonstrate that properly for a few months. It’s been quiet and trouble free so far.
Built house with 16kw gen-1 Daikin heat pump in 2008. Installed replacement 3rd-gen 9kw Daikin heat pump 2025. 5.6kw solar. Heat recovery and ventilation. UFH. Massive insulation.
- 22 Forums
- 2,056 Topics
- 44.9 K Posts
- 64 Online
- 3,293 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
-
RE: How To Balance Radiators & the Role of the Lockshield Valve: A Homeowner's Guide
Good luck, I hope it all works out!
By JamesPa , 27 minutes ago
-
RE: Is Your 6kW Air Source Heat Pump Really a 6kW?
In fairness to heat pump manufacturers the output inevi...
By JamesPa , 30 minutes ago
-
@johnd it's a difficult one, because we've seen instanc...
By Mars , 3 hours ago
-
RE: IVT Greenline high pressure switch and electrical cassette errors
Here are the reported most common causes for both. Co...
By abbote , 3 hours ago
-
RE: Is your heat pump insured?
@johnmo sorry it comes across like that. The post is au...
By KevinPotts , 3 hours ago
-
RE: Getting the best out of a heat pump - is Homely a possible answer?
@johnmo Perhaps a little detail might explain my reason...
By Toodles , 3 hours ago
-
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 , 17 hours ago
-
RE: Yes, the "zoning with ASHP" topic again...
James, thanks again for your thoughtful and persistent ...
By HarryRea , 17 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 , 20 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 , 21 hours ago
-
RE: Battery sizing - How low can you go!
My own experience with connecting four batteries to thr...
By Transparent , 1 day ago
-
RE: Plate heat exchanger considerations
Work on 2-3 percent per degree. This is a reasonable e...
By JamesPa , 2 days 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 , 2 days ago
-
RE: Volumisers in Heat Pump Systems: Does Placement Matter?
You’re absolutely right that during defrost the refrige...
By Mars , 2 days ago
-
@editor thanks Mars that’s the same table I found in th...
By Gary , 2 days 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