Forums

Search with Wattson
Forums
Renewable Heating
Air Source Heat Pum...
Summer usage. Why i...
 
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!

Summer usage. Why is my Vaillant Aerotherm using so much energy on "heating"?

 
Air Source Heat Pumps (ASHPs)
Last Post by AndrewJ 31 minutes ago
2 Posts
2 Users
0 Reactions
25 Views
RSS
 DavidB
(@davidb)
Trusted Member Member
Joined: 3 months ago
Posts: 46
Topic starter 25/04/2026 9:01 am   [#2971]

Hi everyone,  Having had our 3.5 Aerotherm installed Sept 25, only now am I continually operating with heating off.  The following show usage over the past few days.  Can anyone explain why I am using so much “heating” energy when the system is off?  The second screenshot is particularly surprising showing 1kWhr of energy goes into heating to generate 200W of heat - while heating is off?

IMG 2343
IMG 2342

I checked the DHW only information and it shows a COP of 3.27 so the system appears to be using 1 kWhr which is being wasted?  Over the next 6 months, that strikes me quite a lot.


This topic was modified 48 minutes ago by Mars

   
Quote
 AndrewJ
(@andrewj)
Estimable Member Member
Joined: 1 year ago
Posts: 203
25/04/2026 9:52 am  

I don’t know how the Aerotherm works so can’t comment on that.  Looking at the graph, and as long as I haven’t misinterpreted it, it seems to be showing a total usage of 1kW over 6 days plus a few hours today, 7 I think.  That would be 1kW / ((24x6)+7 =0.00662 kWh which is around 7wH.  The second screenshot seems to be showing an efficiency of 2.76 for heating and hot water which, for hot water only, seems reasonable (on the basis that power for “heating” is minuscule.  I expect there is an element of tickover as the system probably has some frost protection built in.  I dare say someone will be along to explain the Aerotherm and why it might be maintaining some heating input.  



   
ReplyQuote
Forum Jump:
  Previous Topic

Currently viewing this topic 5 guests.

Recently viewed by users: AndrewJ 27 minutes ago, DavidAlgarve 48 minutes ago, Mars 48 minutes ago, trebor12345 52 minutes ago.



Share:

Join Us!

Worth Watching

Latest Posts

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