Forums

Forums
Renewable Heating
Air Source Heat Pum...
Peak Energy Product...
 
Notifications
Clear all

Peak Energy Products V therm 16kW unit heat pump not reaching flow temperature

 
Page 5 / 6
Air Source Heat Pumps (ASHPs)
Last Post by DaveC 2 weeks ago
63 Posts
7 Users
8 Reactions
1,535 Views
RSS
JamesPa
 JamesPa
(@jamespa)
Illustrious Member Moderator
Joined: 3 years ago
Posts: 4234
11/01/2026 8:37 pm  

Posted by: @davec
↑

it wasn’t until later when we realised that the WC wasn’t being applied to the set FT that was causing the issue and we started to manually alter the FT to allow the ASHP to back off the compressor frequency and improve the efficiency.

I would describe this as either a fault or a configuration error.  If the ft isn't changing with oat then wc isn't working, your heat pump won't be efficient, and you won't be comfortable.  The installer needs to fix this, as it stands it isn't fit for purpose.  He also needs to explain how to adjust the WC.  Don't accept any excuses this is just wrong!


This post was modified 1 month ago by JamesPa

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
 johnd
(@johnd)
Trusted Member Member
Joined: 9 months ago
Posts: 23
Topic starter 15/01/2026 12:26 pm  

@jamespa I have emailed the installer about the WC, I am yet to receive a response.



   
👍
1
ReplyQuote
 DaveC
(@davec)
Trusted Member Member
Joined: 1 month ago
Posts: 23
15/01/2026 1:30 pm  

@jamespa @johnd just spoken with our installer who also had no response from Peak.

I've asked to chase up the WC issue again. 

Also requested the heating capacity table for the current v-therm ASHP models as the one on the website was from the older model.

Very surprised when it lists our 11kw model as able to provide 11kw of heat down to -3 with a SCOP of 4.2! Something has to be very wrong somewhere.

IMG 20260115 130811386 HDR

11kw Peak Energy ASHP - SunSynk 3.6kW Solar Inverter with 3.5kw panels and GSL 10kWh home battery


   
ReplyQuote



JamesPa
 JamesPa
(@jamespa)
Illustrious Member Moderator
Joined: 3 years ago
Posts: 4234
15/01/2026 2:07 pm  

Posted by: @davec
↑

@jamespa @johnd just spoken with our installer who also had no response from Peak.

I've asked to chase up the WC issue again. 

Also requested the heating capacity table for the current v-therm ASHP models as the one on the website was from the older model.

Very surprised when it lists our 11kw model as able to provide 11kw of heat down to -3 with a SCOP of 4.2! Something has to be very wrong somewhere.

IMG 20260115 130811386 HDR

The good news is that it leaves no excuse if it doesn't do that!

The WC stuff is absolutely basic.  I cant understand how an installer doesn't know how to get WC working on a heat pump he installs, as no heat pump for domestic heating should ever be installed without, with the possible exception of a really good UFH system where the design FT is 30 or less.

 


This post was modified 1 month ago by JamesPa

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
TechnoGeek
 TechnoGeek
(@technogeek)
Reputable Member Member
Joined: 3 years ago
Posts: 163
16/01/2026 11:03 am  

@davec 

Posted by: @davec
↑

Very surprised when it lists our 11kw model as able to provide 11kw of heat down to -3 with a SCOP of 4.2! Something has to be very wrong somewhere.

I kind of read that information as the "unit is capable of supplying 11Kw @ -3C and this has been possibly tested on a system which is configured with a yearly performance figure of 4.2".

If you did a test on a day @-3C the COP I would suspect, would be a lot lower which is not advised in the tech data

 

Regards


5 Bedroom House in Cambridgeshire, double glazing, 300mm loft insulation and cavity wall insulation
Design temperature 21C @ OAT -2C = 10.2Kw heat loss, deltaT = 8 degrees
Bivalent system containing:
12Kw Samsung High Temperature Quiet (Gen 6) heat pump
26Kw Grant Blue Flame Oil Boiler
4.1Kw Solar Panel Array
34Kwh GivEnergy Stackable Battery System


   
ReplyQuote
JamesPa
 JamesPa
(@jamespa)
Illustrious Member Moderator
Joined: 3 years ago
Posts: 4234
16/01/2026 11:24 am  

Posted by: @technogeek
↑

If you did a test on a day @-3C the COP I would suspect, would be a lot lower which is not advised in the tech data

Agree, the figure is given for SCOP not COP

 


This post was modified 4 weeks ago by JamesPa

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



 DaveC
(@davec)
Trusted Member Member
Joined: 1 month ago
Posts: 23
19/01/2026 5:46 pm  

@jamespa and @johnd we had 2 engineers out today from Peak to review the ASHP.

They’ve given the external unit a good once over and checked the firmware on the controller (although it looks to be the same version as before).

It currently appears that the WC is now working as the FT on the home page changes from the set value.

Just checked the level 1, 2 and factory menus and can’t see any values changed, so don’t really know what was done. I wasn’t home as had to be in the office today so can’t comment any further.

Obviously I will be keeping a close eye on it over the coming days.


11kw Peak Energy ASHP - SunSynk 3.6kW Solar Inverter with 3.5kw panels and GSL 10kWh home battery


   
👍
2
ReplyQuote
 johnd
(@johnd)
Trusted Member Member
Joined: 9 months ago
Posts: 23
Topic starter 19/01/2026 6:27 pm  

@davec that's good news! Thanks for sharing Dave.



   
ReplyQuote
 DaveC
(@davec)
Trusted Member Member
Joined: 1 month ago
Posts: 23
22/01/2026 9:41 am  

@johnd, sorry just got a bit more info to share with you.

Spoken with the Peak engineer yesterday and it was him manually adjusting the FT on our system, not the WC working to automatically adjust it…

He’s asked for a couple of weeks to look at the system and adjust ‘some’ settings in the background.


11kw Peak Energy ASHP - SunSynk 3.6kW Solar Inverter with 3.5kw panels and GSL 10kWh home battery


   
ReplyQuote



JamesPa
 JamesPa
(@jamespa)
Illustrious Member Moderator
Joined: 3 years ago
Posts: 4234
22/01/2026 12:31 pm  

Posted by: @davec
↑

@johnd, sorry just got a bit more info to share with you.

Spoken with the Peak engineer yesterday and it was him manually adjusting the FT on our system, not the WC working to automatically adjust it…

He’s asked for a couple of weeks to look at the system and adjust ‘some’ settings in the background.

Im sure you dont need me to tell you not to let him off the hook until WC is working without him playing in the background!

 


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
 johnd
(@johnd)
Trusted Member Member
Joined: 9 months ago
Posts: 23
Topic starter 25/01/2026 10:27 am  

@davec I am in exactly same position, the engineer whatsapp'd me informing me he would monitor for the next few weeks. 🙂



   
ReplyQuote
 DaveC
(@davec)
Trusted Member Member
Joined: 1 month ago
Posts: 23
03/02/2026 5:11 pm  

@johnd We've not had anything back from Peak yet, now 2 weeks after their visit and still no working WC on the system.

Just spoken to our installer who will be chasing them up first thing in the morning.

But we have had our electric bill for the last month for £430! 28th December to 27th January.


11kw Peak Energy ASHP - SunSynk 3.6kW Solar Inverter with 3.5kw panels and GSL 10kWh home battery


   
ReplyQuote



Page 5 / 6
Forum Jump:
  Previous Topic
Next Topic  

Currently viewing this topic 3 guests.



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 →