UFH not working - suspect issues at manifold

[Mjward]

Hello

As per title, the 3 zones of UFH to one manifold are not working.

All is good from an electrical perspective, i.e. the room thermostats are calling for heat, the UFH wiring centre is triggering the boiler, but simply no heat is coming from the floor.

What makes analysis difficult is 1) recently moved in and had the system turn off for long period whilst doing works 2) 2 of the zones are same room, large kitchen with aga oven releasing heat.

Assuming it's an issue at the manifold, what are the things I can test for? The flow meters are gunked up, could that be the cause or indicate whole system needs power flush? It has a grundfos motor but I can't hear anything, but same motor is on different manifold and is silent but working fine, how do I test if motor actually working?

Anything else I can cross off before getting someone out?

Thanks!!

 

[Mjward]

Do the flow meters move at all if you fully close them or open it ?

Unfortunately nothing in either direction. Brand new replaced today.

 

[ShaunCorbs]

Sounds like either no flow or a blockage as they should work as fully open on the flow meter eg all the way out until stop is max then all the way in is off / no flow

 

[Mjward]

I'm guessing from state of old flow meter could be sludge build up. But if it was so bad to not allow any response from the flow meter then I'm confused as to how water was flowing out the drain pipe when I was filling i.e. if enough space around the sludge for water to exit then I would have thought that would be enough water to register something on the flow meter or am I not understanding how they work properly?

Thanks for all this troubleshooting by the way, it really is appreciated

 

[ShaunCorbs]

Did you shut the return and pull through the return side of the manifold ?

 

[Mjward]

Did you shut the return and pull through the return side of the manifold ?

I tried to close the return as soon as the flow meters were almost full but then every time the filling pipe would almost blow off due to pressure and the flow meter water levels dropped off to where they are in previous pics.

To confirm from pic below, red pipe is drain pipe from actuator part of manifold and other pipe is my fill pipe to the flow meter part. Maybe I'm filling/draining from wrong way round but my research saw everyone do it that way. Note after I filled it best I could I turned the red/blue valves to open them.

 

[ShaunCorbs]

No you are correct but the flow meters look shut there eg not much gap between need to close two and one open

Ignore me just noticed the pumps pumping down / into flow meters

 

[Mjward]

No you are correct but the flow meters look shut there eg not much gap between need to close two and one open

But I looks like your manifolds are the wrong way round eg flow meters should be top unless the top valve is the flow ?

Honestly I don't know. There are no obvious markings other than on manifold it says brand name and IN and OUT which I assume resembles flow/return. In which case the red sticker at the bottom has IN.

Worth me flipping these around and put actuators at bottom?

 

[Mjward]

For reference this is the upstairs manifold which is working broadly as intended (although one zone gets too hot and another not enough, I also note no isolation valve for flow/return)

 

[ShaunCorbs]

Does the closest one to the pump get the hottest / too hot ?

 

[Mjward]

I've ordered a digital thermometer (coming tomorrow) as to my touch there is very little difference in the metal part of manifold ie top and bottom bar both hot. Pipes are room temperature coming out from either flow or actuators part

 

[Mjward]

The manifold metal bar ie the part where the UFH pipes are connected, is getting hot on both top and bottom, almost identical on both around 40c. Plastic pipes themselves not warming at all

 

[ShaunCorbs]

Open one flow meter fully open

 

[Mjward]

Thats what I've done so far. Opened one fully, closed two fully, given it some time but nadda. Same for all three loops.

I'm confused how both top and bottom can be hot if loops themselves aren't flowing. I thought only flow side was fed the warm water from the flow mixer. From the piping on mine it looks like there is a connecting (vertical) pipe from the flow mixer that is perhaps simultaneously feeding both top and bottom bars

Open one flow meter fully open

 

[MOSSEP]

It could be that you have inadequate flow to your actual manifold, your main system pump could be the issue. Isolate the other manifold that is working and see if it gives an improvement.