UFH manifold problem

[joe90]

Our heating is not working well, on looking at the manifold (wunda) it has the same temp going in as coming out! The pump is running and I even took the blending valve out so the valve was not causing the problem. Before this we used to get 24’ going in and 20-21 coming out. The pipe feeding the manifold is warm as it was before. I have checked for an airlock. What else can I look for?

 

NOTE above I said blending valve, I meant the TRV head.

Edited January 15, 2019 by joe90

[ProDave]

What do the flow meters show? They should show water is actually flowing through all the loops.

 

If return temp = supply temp then don't discount the slab being up to full temperature.

[joe90]

Yes Dave, flow meters showing flow through all loops, the room stat controls the UFH manifold and that is asking for heat, the supply pipe is warm but it appears not to be flowing into the mixer. Have been told that maybe the mixer valve is blocked so going to drain it and look into that being the problem.

 

in essence I don’t know how the mixer assembly on the manifold works but it appears to be pumping the same water around the loops and not accepting any new warm water.

Edited January 15, 2019 by joe90

[joe90]

Right, think I found the problem. In the return part of the manifold is a sprung plastic valve that I believe gives preference to heated water entering the manifold but if the TRV head says “no more” it allows the return water (cool) to be circulated instead, this valve had come loose and so was allowing only coolwater to be the circulated rather than incoming warm water. ASHP back on (with immersion to help heat the buffer quickly) and will report if it works or not.

[joe90]

Yup, all working as it did before, just goes to show even new kit can go faulty. I recon the valve was never inserted properly in the first place. ?

[ProDave]

Photo of the manifold so we can understand which valve was the issue?

[Temp]

I've had problems with one or two of the wax actuator heads popping off but not the blender as that's a different design on our system. When the loop heads pop off the loop is permanently on.

[joe90]

7 hours ago, ProDave said:

Photo of the manifold so we can understand which valve was the issue?

 

Here is a photo of my manifold, the internal valve or sprung one way plastic valve is in the bottom pipe just to the right of the temp gauge at its threaded joint with the rest of the manifold. To access it the piece needs removing and accessing from either end. It is a push fit with “o” ring into the end of the pipe. Makes me wonder if it was ever fitted correctly. There were small plastic lugs that held it in place so maybe it was not pushed fully home during manufacture?

Edited January 16, 2019 by joe90