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ASHP low UFH Temperature

Featured Replies

Ok that’s a UFH issue as the heat pump works for the hot water. Can you take a photo of the pipework leaving the outdoor unit and the manufacturers plate ..?

Going back you your blending valve, I assume it is this one you are talking about?

 

image.png.e45bc60739b4844461d49d896aca676d.png

 

The bottom pipe is the heating flow into the mixing valve.  Is that remaining warm?  (if it's in the region of 45 degrees it should feel hot to the touch)  or is that pipe cooling down (if it's only 20 degrees it will feel cool or at best barely tepid to the touch)

  • Author

7EECF933-0FE6-4DAB-9A3E-7069A324334A.thumb.jpeg.c9c54f4430457873e1d0143771cb51e3.jpegthe pipe doesnt remain warm below the mixing valve. 

Edited by Dcc

28 minutes ago, Dcc said:

the pipe doesnt remain warm below the mixing valve. 

So does the ASHP continue to actually run when heating is demanded?  I am now wondering of that change of mixing valve has messed up some of the wiring and the ASHP is no longet getting a "call for heat" when the heating is on. 

  • Author

Sorry when you mean the ASHP, you mean the unit in the garden? 

6 minutes ago, Dcc said:

Sorry when you mean the ASHP, you mean the unit in the garden? 

Yes the unit in the garden or the big silver box in the bottom of the cupboard, are either of them making any noise?

What about the circulating pump in that cupboard? is that making any noise? You should usually hear a gentle hum of you put your ear close?

Is the circulating pump next to the two big yellow and red switches making a gentle hum or is it cold and silent?

3C43498B-8C72-4209-B68E-218F2D796482.jpeg

 

Lower down there is a silver box about 80mm square into which the cable from the mixing valve goes (amongst many others)  Two SWA cables emerge at the bottom and I bet they go to the outside unit.

 

If he has (probably inadvertently) messed up the wiring in that box, the ASHP may not be getting a call for heat from the heating.

  • Author

The unit in the garden always seems to be spinning, when hot water is heating all kicks in. When we’re not running any hot water or appliances it starts and the stops to heat the underfloor heating. 

 

 

  • Author

The grundfos pump is humming and slight vibration always

  • Author

I will check that, thanks for your help.

  • Author

I do know when the water is heating up the large silver box inside is noisy and when it starts to heat the ufh it’s noisy, and the pipe into the new valve is very hot, then it will stay at 45 and then goes quite and drops to 20’s

 

but it doesn’t stay hot long enough to heat the UFH.

 

the little silver box you mentioned is for the rain water harvest system which previous owner had turned off.

Edited by Dcc

  • Author

In my head which is probably not correct

 

i was thinking the outdoor unit was working at 70% efficiency, after it was turned new gas etc it was now 100 efficiency.

 

that extra energy/pressure has caused for this valve to get stuck

 

even with the old valve stuck the pipe running into the old valve always seemed hot when I checked it to see if the valve had released. 
 

Basically not had it working since 8th December  so was checking it a lot over xmas.
 

 

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