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!!

 

[ShaunCorbs]

Is the pump flashing or constant led ?

 

[Mjward]

I don't see any obvious lights on either pump. First pic is of problem manifold. Second is of working one.

 

[ShaunCorbs]

Can you feel the pump working ?
Zones open / flow meters moving ?

 

[Mjward]

Can you feel the pump working ?
Zones open / flow meters moving ?

The pump feels warm to the touch but it's not vibrating or anything. No lights. There is a settings lever on one side marked in Roman numerals "I", "II" and "III" (currently set to I) but I don't know what the controls.

The bottom left hand (zone 1) pipe is the only one warm, the top three pipes by actuators and other bottom 2 are not warm.

The flow meters arent showing any sign of movement. Zones indicating open on actuators

 

[ShaunCorbs]

Grab a towel and open the front bleed screw is the impella turning if not use a flat bladed screwdriver to give it a spin

Aslong as there’s 240v at the pump

 

[Mjward]

Grab a towel and open the front bleed screw is the impella turning if not use a flat bladed screwdriver to give it a spin

Aslong as there’s 240v at the pump

Yup opened it up and spinning nicely

 

[ShaunCorbs]

Can you manually remove a head ?

 

[Mjward]

Can you manually remove a head ?

As in a flow meter/actuator? If you let me know what to check for I'll have a crack first thing in morning.

Thanks for your help/patience on this Shaun, much appreciated

 

[ShaunCorbs]

Actuator just incase it’s bad, also check the trv head pin isn’t stuck shut

 

[Mjward]

Actuator just incase it’s bad, also check the trv head pin isn’t stuck shut

Ah I know both are fine, actuators only fitted this week and trv pin was fine

 

[ShaunCorbs]

Are they opening ? / when off does it get warm ?

 

[Mjward]

I've taken actuator off. It's a NC pin, should I be pulling it up with pliers to check it's able to move freely or could that damage it?

 

[Mjward]

In fact I've just tried with pliers and can't get it to move at all.

 

[ShaunCorbs]

Does it push down ? If not try twisting left or right should pop up

 

[Mjward]

Does it push down ? If not try twisting left or right should pop up

It does but I need to apply a lot of pressure and only by a few millimetres, don't know if that's the norm

 

[ShaunCorbs]

Should move more than a few mm

 

[Mjward]

Should move more than a few mm

Would say 2-3mm on all three pins

 

[Mjward]

I'm also wondering, if the pin is up (as I can press down) then surely they should all be receiving hot water ie the flow pipes should be hot. But only the return pipe on the first port (bottom left) is warm

 

[Mjward]

I'm also wondering, if the pin is up (as I can press down) then surely they should all be receiving hot water ie the flow pipes should be hot. But only the return pipe on the first port (bottom left) is warm

Have removed and serviced flow meters and actuators but issue remains and makes sense as above, actuators pins stuck open so if anything I should have had hot pipes from the off. So they work, pump works, there is hot pipework after mixing valve.

Last thing it could be is blocked loop (with sludge) or anything I've missed?

 

[ShaunCorbs]

Only option is to now flush each loop via a hose pipe incase there’s air stuck

 

[Mjward]

Only option is to now flush each loop via a hose pipe incase there’s air stuck

Started to flush and from what I've researched, I should leave first flow meter open and other closed. It's not overly clear but to do that I've unscrewed the glass portion as much as possible anti clockwise and tightened the other two clockwise. However the flow meter does not move/respond to the water flow which is exiting into my bucket without sputtering/air.

For reference I'm filling via the flow meter portion and draining via the actuator portion of the manifold

 

[ShaunCorbs]

No water in the flow meters also just close the actuators on two of them

 

[Mjward]

Getting some where, but can only partially fill the flow meters before the pressure blows the filling pipe off (despite it draining out the other side).

I've turned the main valves back on and got pump running to call for heat, actuators working but the flow meters just zero response, stuck showing 0 flow

 

[ShaunCorbs]

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

 

[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