Renewable Heating Hub Heat Pump Forums

Search with Wattson
Forums
Renewable Heating
Air Source Heat Pum...
Grant R290 DHW Cycl...
 
Notifications
Clear all

Joining the Renewable Heating Hub forums is completely free and only takes a minute. By registering you’ll be able to ask questions, join discussions, follow topics you’re interested in, bookmark useful threads and receive notifications when someone replies. Non-registered members also do not have access to our AI features. When choosing your username, please note that it cannot be changed later, so we recommend avoiding brand or product names. Before registering, please take a moment to read the Forum Rules & Terms of Use so we can keep the community helpful, respectful and informative for everyone. Thanks for joining!

Grant R290 DHW Cycle Interuption

 
Air Source Heat Pumps (ASHPs)
Last Post by JamesPa 1 month ago
2 Posts
2 Users
0 Reactions
422 Views
RSS
 Steam Powered
(@steam-powered)
Active Member Member
Joined: 2 years ago
Posts: 15
Topic starter 19/09/2026 9:43 am   [#3168]

I have just had a Grant R290 9Kw HP installed to replace my Grant R32 15kW unit which was way oversized against my 7.2kW heating requirement. After two winters of short cycling, high power consumption and a lot of frustration enough was enough!

Having tested it as best I can in mild weather it looks very promising. I have one bug which I will discuss with the installer but would also like to share here to see if anyone else has experienced it. I have DHW programmed twice per day, 04:00 & 14:00. Over sixteen days of operation three of the am DHW cycles have been interupted for a few minutes and then resumed. The attached trace shows one of these. They were at 04:04, 04:07 and 04:09 and each for around three minutes.

Clearly not a huge issue, but something I would like to resolve if possible. Does anyone have any experience of the same or suggestions please?

DHW cycle short drop out 19.09.26.pdf

 

 



   
Quote
JamesPa
 JamesPa
(@jamespa)
Illustrious Member Moderator
Joined: 4 years ago
Posts: 5586
19/09/2026 1:22 pm  

It looks like some sort of short pre-run.  The question is, do other grant owners see the same? 

 

Is there any kind of 'live' display, possibly in the installer menu, telling you what the heat pump is currently doing?


4kW peak of solar PV since 2011; EV and a 1930s house which has been partially renovated to improve its efficiency. 7kW Vaillant heat pump.


   
ReplyQuote
Forum Jump:
  Previous Topic
Next Topic  
Share:

SPONSORS

Join Us!

Installer Finder

Degrees of Separation

Latest Posts

SPONSORS

Click to access the login or register cheese
Protected By
Shield Security PRO