Forums

Forums
Renewable Heating
Air Source Heat Pum...
Baxi Air Source Hea...
 
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. 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!

Baxi Air Source Heat Pump tips and tricks

 
Page 4 / 10
Air Source Heat Pumps (ASHPs)
Last Post by Broadsman 12 months ago
109 Posts
7 Users
54 Reactions
15.8 K Views
RSS
cathodeRay
 cathodeRay
(@cathoderay)
Famed Member Moderator
Joined: 4 years ago
Posts: 2836
09/02/2025 4:29 pm  

Posted by: @transparent
↑

You shouldn't be getting a lukewarm bath if the tank temperature is 50°C.

When it is highlighted (selected, as it was in the image in the post), it is showing the set temperature, not the actual temperature. It shows the actual temperature when it is not highlighted.

@cathyem1 - assuming the default DHW heating comes on when DHW falls five degrees below the set DHW temp, and a set DHW temp of 50, what you are looking for is a rise in the actual DHW temperature when it falls below 45 degrees back up to 50 degrees. Have a look at it every now and then, and see if you can see that pattern of behaviour.

Or just wait until your supplier turns up tomorrow!

 


Midea 14kW (for now...) ASHP heating both building and DHW


   
ReplyQuote
 Cathyem1
(@cathyem1)
Trusted Member Member
Joined: 1 year ago
Posts: 59
Topic starter 09/02/2025 5:25 pm  

@cathoderay thank you. Very interesting that the temperature it is showing when not highlighted is the actual temp.

I have just had a lovely hot bath and the temp is now showing at 13°. 



   
ReplyQuote
cathodeRay
 cathodeRay
(@cathoderay)
Famed Member Moderator
Joined: 4 years ago
Posts: 2836
09/02/2025 6:34 pm  

Posted by: @cathyem1
↑

I have just had a lovely hot bath and the temp is now showing at 13°. 

Excellent (the hot bath)! Since the actual temp is now way below the 50 degree set temp, it should switch to DHW heating mode and get back to 50 degrees. When it is not on a timer, the DHW priority (over space heating) should mean that whenever the tank is five of more degrees below the set temp, it goes into DHW heating mode. Have another look in ah hour and see what it shows then.   


Midea 14kW (for now...) ASHP heating both building and DHW


   
👍
1
ReplyQuote



 Cathyem1
(@cathyem1)
Trusted Member Member
Joined: 1 year ago
Posts: 59
Topic starter 09/02/2025 9:19 pm  

@cathoderay Our 01.00 to 06.00 electricity tariff is going to be 5p kWh. Is it possible to set the DHW to heat overnight?

 



   
ReplyQuote
cathodeRay
 cathodeRay
(@cathoderay)
Famed Member Moderator
Joined: 4 years ago
Posts: 2836
10/02/2025 7:51 am  

Posted by: @cathyem1
↑

Our 01.00 to 06.00 electricity tariff is going to be 5p kWh. Is it possible to set the DHW to heat overnight?

Yes, but first of all we need to know the DHW heating is working. Did the actual DHW temperature rise after it went down to 13 degrees yesterday after your bath?


Midea 14kW (for now...) ASHP heating both building and DHW


   
👍
1
ReplyQuote
Transparent
 Transparent
(@transparent)
Famed Member Moderator
Joined: 4 years ago
Posts: 3093
10/02/2025 10:13 am  

[aside] I'm impressed how much @cathyem1 is picking up from this discussion and diagnosing what's going on. 🤗 

This is just the sort of background knowledge which needs to spread across the rest of the population.

I hope the meeting with the installer goes well today.
Please let him/her know of this topic.


Save energy... recycle electrons!


   
👍
2
ReplyQuote



 Cathyem1
(@cathyem1)
Trusted Member Member
Joined: 1 year ago
Posts: 59
Topic starter 10/02/2025 12:47 pm  

@transparent It did go well! The timer has been set for our DHW to heat in our 5p kWh window overnight and he’s brought our flow rate down to 40°. He was slightly pursed-lipped when I asked and did say the parts of the control panel that do that aren’t really for the customer - read Muggle 😉

I'd already found the pass code and guidance for changing the heat flow on the CP via Youtube - so I told him the code 🫢

Anyway, upwards and onwards. Hopefully we’ll feel just as snug tonight for less money 💵 



   
ReplyQuote
 Cathyem1
(@cathyem1)
Trusted Member Member
Joined: 1 year ago
Posts: 59
Topic starter 10/02/2025 12:51 pm  

@cathoderay You’re on fire!! The installers had put the temperature sensor into the wrong pocket on the cylinder, so the heat pump was permanently trying to heat the DHW. Explains why I kept having to override the system to warm the house 😉



   
🤦‍♀️
2
ReplyQuote
cathodeRay
 cathodeRay
(@cathoderay)
Famed Member Moderator
Joined: 4 years ago
Posts: 2836
10/02/2025 1:10 pm  

@cathyem1 - 2 3 4 and through the door...

Posted by: @cathyem1
↑

The installers had put the temperature sensor into the wrong pocket on the cylinder,

I had that thought and then discounted it on the grounds they couldn't be that dumb. The sad lesson is never under-estimate how dumb 'the professionals' can be. Harsh, but true.

Posted by: @cathyem1
↑

he’s brought our flow rate down to 40°. He was slightly pursed-lipped when I asked and did say the parts of the control panel that do that aren’t really for the customer

'aren't really for the customer'??? Whose heat pump is it anyway? I think it may be that he has left the system on a fixed flow temp (not rate, rate is the amount of water over time, not its temperature, though both matter) of 40 degrees, which means it is still not on weather compensation. The 'at a glance' way to tell is by what you can see on the left hand heating side panel on the wired controller if you select the big number in the middle there and use the up or down arrow to try to change it. If the display then says 'Weather temp set function is on. Do you want to turn it off?' then you are using weather compensation (so back out without changing anything). If you can change it, then you are not using weather compensation.  

 


Midea 14kW (for now...) ASHP heating both building and DHW


   
ReplyQuote



 Cathyem1
(@cathyem1)
Trusted Member Member
Joined: 1 year ago
Posts: 59
Topic starter 10/02/2025 1:54 pm  

@cathoderay It looks like we are using weather compensation!!!

IMG 3569


   
ReplyQuote
Transparent
 Transparent
(@transparent)
Famed Member Moderator
Joined: 4 years ago
Posts: 3093
10/02/2025 2:43 pm  

Apologies for not addressing this earlier

image

The Red knob is an over-temperature/pressure relief valve.

In the event of a fault, it will allow the scalding hot water to be discharged rapidly into the tundish below it,
and then routed to the outside via the larger pipe connected at the outlet.

... except that the tundish and safety pipe aren't present.

So in the case of @cathyem1 's installation, the pressure will build up until it overcomes the friction of the rubber o-ring in the white end-cap.
That projectile will be propelled into the insulation of the pipe below it...

Fortunately, the noise should be sufficient to wake up the household. 😯 


Save energy... recycle electrons!


   
ReplyQuote
 Cathyem1
(@cathyem1)
Trusted Member Member
Joined: 1 year ago
Posts: 59
Topic starter 10/02/2025 3:00 pm  

@transparent Yikes! I wish I'd known that when the chap was here, but thank you for bringing it to my attention.



   
ReplyQuote



Page 4 / 10
Forum Jump:
  Previous Topic
Next Topic  

Currently viewing this topic 1 guest.



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 →