Renewable Heating Hub Heat Pump Forums

Search with Wattson
Forums
Renewable Heating
Air Source Heat Pum...
Preparing for 2nd w...
 
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!

Preparing for 2nd winter in new build house.

 
Page 2 / 2
Air Source Heat Pumps (ASHPs)
Last Post by Transparent 1 year ago
16 Posts
5 Users
1 Reactions
3,331 Views
RSS
 sbm74
(@sbm74)
Active Member Member
Joined: 1 year ago
Posts: 9
Topic starter 19/09/2025 12:34 pm  

The setting is on the room stats. That room has 2 loops. The ASHP is using weather compensation so the OAT would have to be around -15° before it got to 60°.  According to the heat loss calcs the maximum flow temp should be 50°.



   
ReplyQuote
Carpenterstation
 Carpenterstation
(@carpenterstation)
Trusted Member Contributor
Joined: 2 years ago
Posts: 50
19/09/2025 12:56 pm  

Welcome to the forum. I am commenting as there are similarities with our property. Relatively “new” build and 450m2 and 250m2 ground floor is all UFH.

 

Our install was not great (temps far too hot, excessive cycling, heat literally thrown away by a diverter when circulating temp was too high).  We fixed by setting all in room thermostats to 20 degrees all the time acting as limiters, set the upstairs to 18deg, reduced flow temp to 32degees and switched on weather compensation. After a few weeks of tweaking w/c, system settled down - and the house is now permanently warm enough.

efficiency isn’t everything. You need to be careful that you aren’t  just efficiently producing too much heat. 

 

 



   
👍
1
ReplyQuote
 sbm74
(@sbm74)
Active Member Member
Joined: 1 year ago
Posts: 9
Topic starter 19/09/2025 1:46 pm  

@carpenterstation Good to know. Looks like that's the way forward.



   
ReplyQuote
Transparent
 Transparent
(@transparent)
Illustrious Member Moderator
Joined: 5 years ago
Posts: 3401
19/09/2025 2:43 pm  

Posted by: @sbm74
↑

The setting is on the room stats.

Yuch!

So that's basically just an on/off control.

It either lets water flow through a loop at anything up to 60°C, or it doesn't.

 

The thermal lag for UFH within screed will be at least an hour.
My kitchen/diner area (9m x 4m) has a lag of around 4hrs with <40°C flow.

Measuring the air temperature in the room is next to useless.

The 'correct' approach is to remove the thermostatically-operated valve on the manifold.
Fit a manual valve, and adjust it to maintain a steady flow.

IOW you're using it like a lock-shield valve on radiators, to balance the flow throughout all UFH loops.

The longer the loop, the more open the manual valve will need to be.


Save energy... recycle electrons!


   
ReplyQuote
Page 2 / 2
Forum Jump:
  Previous Topic
Next Topic  
Share:

SPONSORS

Join Us!

Installer Finder

Degrees of Separation

Latest Posts

SPONSORS

Members Online

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