Forums

Forums
Renewable Heating
Air Source Heat Pum...
Installer Fitted 9k...
 
Notifications
Clear all

Installer Fitted 9kW Instead of 11kW Heat Pump and Changed MCS Paperwork - What do I do?

 
Page 10 / 10
Air Source Heat Pumps (ASHPs)
Last Post by MairiA 2 hours ago
110 Posts
8 Users
38 Reactions
3,123 Views
RSS
 MairiA
(@mairia)
Estimable Member Member
Joined: 2 months ago
Posts: 41
Topic starter 13/01/2026 4:58 pm  

@editor I have now been allocated a complaint handler by NAPIT. The email advising me of this states 'In accordance with our formal complaint's procedure, we have now referred this matter to our technical team for an initial review. This is to determine whether any technical issues are present that may have contributed to the concerns raised.

Should the review identify any such issues and further action be deemed necessary, we will contact you to advise on the next steps.'
I'll keep you posted!


   
👍
2
ReplyQuote
 MairiA
(@mairia)
Estimable Member Member
Joined: 2 months ago
Posts: 41
Topic starter 13/01/2026 5:20 pm  

@jamespa thank you again. I know using the offset to try to raise the room temperature isn't ideal, but I was desperate! It was one of those times when the LWT wasn't reaching near what it should according to the WD curve. However I have adjusted the curve very slightly to 50 at -2 instead of -3. I've had a look at the installer's manual which I was given a copy of. It's as badly written as the user's manual. But interestingly there is a table showing 'space heating setpoint range' which is maximum 55 for underfloor heating and maximum 60 for radiators - which I have. My system is set to 50 maximum but I've had a look at the installer settings and can see how to increase that to a maximum of 60. Is that worth trying? I have always been puzzled as to what happens when as you mention it reaches the low temperature at which the curve flatlines and can't respond any further to falling temperatures. I'm thinking on the very cold days it may well have been -5/-6 or lower overnight and the house has dropped in temperature and the ASHP is just scrabbling all day trying to reverse that? No doubt it won't be good for my SCOP but my priority is being comfortable over cost.

As far as I can see there is no way to push the system to use purely the immersion heater for DHW, and I'm afraid my skills wouldn't stretch to the kind of modification that you have made. I would likely have to speak to the service company about that.

I wonder about initially changing the setpoint to 55 or 60 and seeing how I get on in the next cold snap. I would greatly appreciate your thoughts on that. Many thanks.



   
ReplyQuote
Page 10 / 10
Forum Jump:
  Previous Topic
Next Topic  

Currently viewing this topic 3 users ( Sheriff Fatman, Mars, MairiA ) and 9 guests.

Recently viewed by users: Transparent 48 seconds ago.

Share:

Join Us!

Worth Watching

Latest Posts

Click to access the login or register cheese
x Powerful Protection for WordPress, from Shield Security
This Site Is Protected By
ShieldPRO →