Polypipe underfloor heating

Matt74 · Mar 8, 2019

Hi
I have a polypipe multizone underfloor heating system (Gas) that stopped working a few weeks ago.
It had been making some screeching noises and my hunch in that the Grundfos pump has died as the screeching has stopped - along with the heating! I may be wrong of course.
The LED's on the side of the pump are not lit.
Pics of control units attached.
Hot water and radiators are fine. Its just the underfloor that has stopped.
I took out the central pump screw and the spindle is turning freely so I don't think its blocked.
It's cool to the touch also so I'm wondering of its a fuse ?
Any help would be appreciated.

Gasmk1 · Mar 8, 2019

you can check the pump very easily if running should be vibrationg or if you can remove the silver screw from the middle some water may come out and check to see if the pump is spinning (so long as there is a call foir heat)if it isnt try turning the pump rotor using a small screwdriver if it is stiff and wont turn (should turn easy) then pump is goosed new one required you need a grundfos ups 25 40/60 or equivalent model

Gasmk1 · Mar 8, 2019

your pump light is not lit either so you need to check if there is power to pump

Chuck · Mar 8, 2019

Matt74 said:
It had been making some screeching noises

That noise was something saying "I'm about to die, it's time to call a heating engineer"

Based on your description of the symptoms, assuming the screeching was continuous while the UFH was on, you will probably need a new pump installed. It's also possible that by leaving it to die it's overloaded the control unit. If you're lucky this won't have caused any permanent damage but it'll need checking.

The fact you were willing to ignore screeching tells me that you are not competent to treat this as a DIY job, so contact the firm who installed it or, if it's out of warranty, a reputable local heating engineer. Expect a bill of a couple of hundred quid plus, pumps are quite pricey these days.

Matt74 · Mar 8, 2019

Think it may be a power supply issue. No idea how to check that though.

Matt74 · Mar 8, 2019

Chuck - at the time I didn't realise where the noise was coming from and it happened at random times so could never isolate the source.

Matt74 · Mar 8, 2019

Hot water and radiators are fine. Its just the underfloor that has stopped.
I took out the central pump screw and the spindle is turning freely so I don't think its blocked.
It's cool to the touch also so I'm wondering of its a fuse ?

Also - What does this thing do?

Chuck · Mar 8, 2019

Matt74 said:
Chuck - at the time I didn't realise where the noise was coming from and it happened at random times so could never isolate the source.

Fair enough. If you are competent to use a multimeter and work on mains wiring have a go yourself. What's the worst that can happen...?

Matt74 · Mar 8, 2019

Chuck said:
Fair enough. If you are competent to use a multimeter and work on mains wiring have a go yourself. What's the worst that can happen...?

Constructive - thanks Chuck
Any other ideas GasMk1?

Matt74 · Mar 8, 2019

Who knows what the white box with the blue connector is?

Chalked · Mar 8, 2019

Matt74 said:
Who knows what the white box with the blue connector is?

It’s where one of your problems is.
It’s a motorised valve. Once this opens, it sends a live to the pump.
So it looks like you motor on the motorised valve has gone, and possibly the pump.
Pump could just be air causing the noise.

Murdoch · Mar 8, 2019

Is the room stat working? I’m assuming there is a stat in the room where the UF heating is?

Matt74 · Mar 8, 2019

It's multi zone system. There are 6 zones. Each with a remote stat.
Chalked - why do you think the motorised valve has gone?

originalracingsnake · Oct 29, 2019

Did you get this fixed? If so, what was the fix?

Murdoch

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