Polypipe underfloor heating not heating up properly after a few years

[warmer82]

Had polypipe underfloor heating installed around 4 years ago. Flow rate used to be around 2.5 l/m now its just over 1 l/m. Tiled floor now is heat patches
I have a nest connected to this also. And 3 zones come on at once in same port on slave unit

I've changed the pump, diverter valve and mixing valve with no change in performance. Also I've connected a hose for each of the 3 zones which I get 3 l/m. I don't know what else to do. Ay help?

 

[EvilDrPorkChop]

There's a filter in the top inlet, however looks like you've changed that?

 

[warmer82]

There's a filter in the top inlet, however looks like you've changed that?

I've changed almost everything apart from the manifold

 

[warmer82]

What I have noticed tho.... if I wind down the first flow metre it goes to 0 but the second and third do nothing when I close

 

[ShaunCorbs]

I think your pump is set wrong it’s on pressure instead of constant as the 3 lights arnt illuminated

Press and hold the setting button for 3 seconds then it should be on constant if the leds are flashing press and hold for another 3 seconds

 

[warmer82]

I think your pump is set wrong it’s on pressure instead of constant as the 3 lights arnt illuminated

Press and hold the setting button for 3 seconds then it should be on constant if the leds are flashing press and hold for another 3 seconds

I did change that earlier. it's on cont curve 1.. the first 3 lights...
Been on cont curve for 2 hours with no difference

 

[ShaunCorbs]

And the pump is correct eg pumping away from the mixing valve ?

 

[warmer82]

And the pump is correct eg pumping away from the mixing valve ?

Arrow is pointing down away from mixing valve

 

[ShaunCorbs]

That’s correct

And the old pump was a 15-60 ?

 

[warmer82]

That’s correct

And the old pump was a 15-60 ?

I don't know what it was... was a while ago. As I brought another ups3 so its had 3 pump changes. Can't remember the first one.

 

[warmer82]

When I have underfloor heating on only the system boiler has a c and burner flashes. When I turn on central heating c comes on and burner light is solid. Boiler is icos 12he.
I assume its a circulation problem

 

[ShaunCorbs]

I would say