Had to replace my GSHP due to new regulations with an ASHP - Ground Source Heat Pump (GSHPs) https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/ Questions and discussions about renewable heating and heat pumps en-GB Wed, 14 Oct 2026 11:19:42 +0000 wpForo 60 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16190 Sat, 11 Feb 2023 08:36:15 +0000 That’s good. 
UV been good for February, 86 kwh so far, I can see the battery storage getting later every day before running out.

]]> Ground Source Heat Pump (GSHPs) Murchison2003 https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16190 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16188 Sat, 11 Feb 2023 08:30:36 +0000 @murchison2003 not too happy re fiddling with the system and valient dont make most user friendly systems but our historic SCOP is sitting at 3.53 going back to last week in feb last year. I am certainly saving money on my old LPG and wood burner i recon we are over £1k saved plus the house never drops below 17.5 and 19.5 daytime  I'm retired so here all day. With 8kwh ground based sp with 9.5 kwh battery just in we are currently pulling in 10kwh per day (early feb!!) so hope savings will all add up

this is all in a 60% 200+ yr old scottish random stone 5 bed cottage.

]]> Ground Source Heat Pump (GSHPs) Sapper117 https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16188 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16187 Sat, 11 Feb 2023 07:24:51 +0000 Every house is different but from what I’ve seen so far 1.2 seems a bit high. But if it’s working and you’re happy with it don’t change it. 
I changed my settings yesterday, curve is at 0.5 now and see a difference but it is 9.5 deg at the moment. Saw the efficiency at 5.2 during the night and has dropped back to 4.8 at the moment. Temp due to drop tomorrow night to just above zero so will monitor that to see how it fairs. 
what efficiency are you seeing with your current settings?

]]> Ground Source Heat Pump (GSHPs) Murchison2003 https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16187 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16186 Sat, 11 Feb 2023 07:13:51 +0000 @murchison2003 thanks I’ve just noted you did say that! Old age!!

we are set at 1.2 but I have two 7kwh Callie TD one acting as DHW and slave to the second which is the main heat. I am not sure if I adjust the heating pump what I should do to the slave especially as everything has worked well for 11 months 

]]> Ground Source Heat Pump (GSHPs) Sapper117 https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16186 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16168 Fri, 10 Feb 2023 16:26:51 +0000 It’s been at 0.4 since Tuesday, I’ve increased it this morning to 0.5 just to see if I can see any difference in temperatures and / running costs for a few days

]]> Ground Source Heat Pump (GSHPs) Murchison2003 https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/paged/2/#post-16168 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-16166 Fri, 10 Feb 2023 16:16:06 +0000 Hi

what do you have your heat curve set at now?

]]> Ground Source Heat Pump (GSHPs) Sapper117 https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-16166 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-16165 Fri, 10 Feb 2023 16:07:07 +0000 My original question was regarding the running costs as my pump ran at 5 kw no matter what. 

After a bit of YouTube research combined with a visit from my installers to check the settings, I found that my heat curve was at 1.9, how that happened nobody knows. My efficiency was about 2.6 and was chewing through the kWh. Some parts of my house were cool and knew there wasn’t something just quite right. 
So after some consultation and the installer playing with the settings, I trialled the curve, adaptive curve setting off and running on weather compensator, we starting the heat curve setting at 0.4 for a few days with the pump practically running all the time keeping the flow temp constant around 28-30 deg. Result is there’s a huge difference in the efficiency which is now showing 4.6 on the heating but it is 10 deg today, the temp one night was 2.5 deg where the efficiency fell to 3.7, still ok for an air source pump. The whole house is staying constantly at 22/22.5 deg 24/7 and the electric consumption of the pump apart from when it’s heating the Dhw has been 1-1.5 kWh. 

I’m still trialling the settings, I’ve increased the heat curve today to 0.5 to monitor heat and consumption for a few days but overall I’m a lot happier with the set up now. 


Another thing we have to remember is that electric costs have trebled in the last year. I’m lucky that I installed more Solar pv last year with battery storage which is now starting to reap rewards as the longer days and increased uv is starting to kick in. My initial expectation was to hopefully be virtually off grid between March and September so we’ll see what happens as the year progresses. 

]]> Ground Source Heat Pump (GSHPs) Murchison2003 https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-16165 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-14272 Mon, 16 Jan 2023 14:07:25 +0000 Groundsource is usually a lot simpler - a lot of them are just simple on/off things just like an old fridge, controlled by relays and thermostats.  There's not a lot of pressure to improve them to inverter designs which are more efficient.  In contrast almost all ashp are inverter units, the R&D budget coming from the enormous volume of air conditioners sold around the world.  Inverter units are quieter that on/off ones, and I think that this is the major attractor to them for A/C and ashp, in order to keep the unit quiet.  In contrast, the gshp is often in a box somewhere, and hopefully can be made quiet that way.

The gshp->ashp differences I would expect are that the (inverter ashp) power level can be increased with little penalty - the only penalty is that weather compensation is now needed to give the best efficiency due to that extra power.  Those old on/off gshp would have been rated closer to the actual demand - if it was over-rated then efficiency would suffer as the radiators would get hotter than needed.

In short - if it's plumbed well(many are not), confirm that weather compensation is on, Ideally find out how to set it yourself.  Modern inverter ashp I think can give similar COP to old clunky on/off gshp.

 

]]> Ground Source Heat Pump (GSHPs) robl https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-14272 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-14262 Mon, 16 Jan 2023 07:51:24 +0000 Yes had the heat loss calculations done and I’m happy with the system installed, I have an A+ house according to my latest EPC which was done 6 weeks ago. 
I can’t check the settings just now as I’m away from home however my installer is aware and are going to come out and check the settings. To be fair, the house runs at 21-22 deg 24/7. 

]]> Ground Source Heat Pump (GSHPs) Murchison2003 https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-14262 RE: Had to replace my GSHP due to new regulations with an ASHP https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-14254 Sun, 15 Jan 2023 21:15:49 +0000 During the winter months from the start of December to March, the brine coming into the pump was usually around 1 degree to zero and leaving the unit at -4. Over the 14 years I had the pump, the auxiliary heater had only 454 hrs on it . This is why I wasn’t really overly concerned about the pump working properly. Only difference that I’m noticing is that my ground source I pump ran at 3kw while this one runs at 5kw. It’s only for a couple of months hopefully that it will be having to do a good bit of work then the solar and batteries will compensate for the running costs. 
I’ll be able to fully compare running costs fully over a full year. 

Has your ASHP been correctly commissioned and optimised, since 5kW seems rather excessive. What are the operating parameters and operating mode? Do you have heat loss calculations for your home?

 

]]> Ground Source Heat Pump (GSHPs) Derek M https://renewableheatinghub.co.uk/forums/renewable-heating-grounds-source-heat-pump-gshps/had-to-replace-my-gshp-due-to-new-regulations-with-an-ashp/#post-14254