UFH Help Please

[padstar]

I now have the UFH connected so that when the stats call for heat, the pump starts and the boiler kicks in.

I have the temp set to 45' on teh mixer and the temp guage is showing just over 40' so that all looks good.

The pressure gauge is showing circa 2 bar so also good.

I set up all the stats yesterday but when they all called for heat i noticed that the flow bar of the manifold was hot but the return bar remained cold. On closer inspection, I found that the flow valves were all closed. This explained the hot and cold bar of the manifold.

I started opening the valves and could see water running through the loops and back. The longer it was left on the less air pockets that i saw flowing past. again this made sense.

Each time i opened up a flow valve the pump consumption power dropped and then picked up as water began to flow (ranged from single digits to mid 30's on the pump power meter). There was a bit of bleeding air from the manifold (mainly on the return bar) and a small top up of the system was also required.

The above made some sort of sense to me BUT i was expecting the red markers on the flow guages to move and wanted to set them to just under 2 bar just to get some heat in the house but they just stayed at the top which i understand to be no pressure?

What am i doing wrong and how do i get this system running heat into the house.

Any help would be much appreciated. Its getting cold out there..

 

[oldbutnotdead]

Looking at the markings on the red valves, I suspect those are flow meters rather than pressure meters. Indicator at the top = no flow, not ideal but maybe the mats are airlocked? Is the return manifold getting at all warm?

 

[MeldrewsMate]

The two circuits shown in your photos are blanked-off at the flow port, so I would expect no flow. Assuming you have other circuits attached unscrew the white plastic cap or remove the electric actuator atop the lower manifold. Does the flow increase on the flow indicators (it has nothing to do with the static pressure in the system). Use a bleed key on the square headed flow adjuster on the lower manifold to restrict the flow to about 2 (midscale), then move on to the next circuit. As more water is pumped the power absorbed from the pump will increase and will be shown on the scale. The final flow settings are determined by the design of the UFH, so refer to that documentation; my suggestions are just that, something to get you started.

MM

 

[Madrab]

By the looks of it the flow meters are airlocked so they won't register flow correctly. There may be flow but the meters would usually need some water in them to register properly

Who commissioned the system, the flow and return side of the manifold should have been properly bled during and as part of the fill.

2 bar is a little on the high side, you system shouldn't need more than 1.5bar hot.

 

[padstar]

Thanks everyone. There are 3 loops on the left hand side that are yet to be installed and are blanked off (as i am still working in these rooms. The UFH company will commission it when these are complete but i want to get some heat in the house now on teh loops that are installed.

The meters on each loop are indeed flow not pressure meters.

There is definitively flow round the pipes as i can see every now and then an air bobble move through the pipe to the return.

The flow meters being air locked would make sense as there is definitely flow but not registering on the meters. How would i resolve this matter?

 

[oldbutnotdead]

I'm no expert but this looks sensible This.
Specially the bit about filling through the flow (which in your case didn't happen)

 

[martygturner]

Fill the circuit properly

 

[Madrab]

You will need to isolate flow and return, de-pressurise all the UFH circuits and then fill via the flow and bleed through the return, the video shows it very clearly. You can't do the initial fill of the UFH circuits via the flow and return of the CH system, which looks like has happened here.

 

[padstar]

This looks like what the pipe installer did. He filled it and left it under pressure a few weeks back. Could it be that air has made its way round and needs topping up or do I need to re fill in the same way?

 

[Madrab]

This looks like what the pipe installer did. He filled it and left it under pressure a few weeks back. Could it be that air has made its way round and needs topping up or do I need to re fill in the same way?

Nope, it shouldn't work like that, when the circuits are filled then they are run until the majority of the air is bled out of the pipework, hence filling it from the flow side so all the air is pushed to the return side and doesn't work it's way back. If there is any left and it does bubble up the flow side, then there should be an air bleed valve at the highest point of the manifold to catch it.

If it was filled correctly, that wouldn't have happened. It needs done properly I'm afraid, that is if you want the flow meters to work correctly.

 

[padstar]

Ok I will refill myself and hopefully all then works

 

[Bodgedbuild]

I'm not a plumber but when my UFH was filled, the guy said it must be filled from the top part of the manifold and not the bottom. This seemed odd to me but he explained it is so that the flow meters are pushed open rather than pushed closed by the incoming water. He did this after the initial plumber failed to clear the air out of the system and it worked a treat.....

 

[padstar]

I had aplumber in yesterday doing some other work. He re filled the system and it seemed to be working last night when i got home with noticeable heat coming into the rooms with UFH where they had been very cold before.

Glad that the system seems to be working BUT the flow meters are still parked up at the top even though there is obviously flow going through the loops. If these are full of air how do i clear them so that the meters operate correctly.

 

[Madrab]

You will need to isolate flow and return, de-pressurise all the UFH circuits, drain out the top of the manifold and then close all the flow meters, fill via the flow and bleed through the return and open one flow meter at a time.

 

[padstar]

Sorry. Its early. Thanks Madrab