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Underfloor heating not making temperature

timtim2016

Good evening, quick query regarding underfloor heating and not making temperature.

We have just moved into a new build house. The front room seems to be constantly running as it never meets the set temp (21c) and always has chill in the room.

The room has a window (floor to ceiling and wall to wall)with no curtain, we have put down semi engineered flooring ( about half inch thick). Would the combination of these two affect the UFH or do we have other issues?

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dmcdona

Hard to determine in the basis of that info. I'm not an UFH expert but we have it upstairs and down. Some questions that might narrow the cause:

what direction does room face (nesw)?

whats your BER?

what temp can the room hold?

are all other rooms holding their temps?

do you know if the installer balanced the system?

timtim2016

Room (the wall with window) faces directly east. Ber reported to us when we bought the house was A3. Room hovers around 20c according to the control panel in the room, which isn't cold but the room feels chilly. The kitchen is the opposite, it always seems to be up at 23/24c even though it's set to 21. The system was commissioned if that's the same as balancing?

Lenar3556

Why is the kitchen getting to 23/24 if the stat is set to 21? Is there significant heat coming from another source?

It might be worth turning up the stat in the kitchen to the max and see does it raise the temp in the sitting room - there is a possibility that the wiring has simply been mixed up between the two zones. (i.e kitchen stat is controlling sitting room, but never switching it on because it is always above set temp, and sitting room stat is controlling kitchen and is calling for heat continuously as the temp in the sitting room is below the set point.)

timtim2016

I'll try that.

The hallway has the same flooring but has an 'open loop' heating and you can feel the heat underfoot. But the living room floor is always cold.

blackbox

https://www.boards.ie/discussion/comment/121419589#Comment_121419589

If the floor is cold but other room with same flooring has a warm floor, you have eliminated the flooring material as being the cause.

If the floor is cold you have also eliminated heat loss through the window.

The problem is either in the thermostat or else the flow of water is restricted/insufficient.

Have you tried simply turning the thermostat up to max? Can you hear anything happening at the control valves as you adjust it?

timtim2016

I have set the the thermostat in the room to 30c now, will report back on a few hours if any change. Could restricted flow vs something simple to fix or issue with the pipework?

timtim2016

Looks like an issue with the pipework in the room, floor has remained cold. Will contact installer tomorrow and see if they can remedy, hopefully something small. Thanks a million for the help

dmcdona

We have a similar setup - open loop for bathrooms (always on). But we have concrete floors. So you really feel the difference in bare feet. However, the "heat" in ufh is very different to rads. When we first moved in, we didn't feel the heat - rather, there was just an absence of cold.

with an A3, I doubt the window is an issue. The BER report would have shown up any unintended air leakage or underperformance.

we had a similar issue when first move in. Master bedroom was particularly cold. Room stat indicated it could reach temp. The installer had it sorted in few mins - a simple adjustment of the water flow.

hopefully thats how this will go for you and you'll be toasty in a jiffy.

good luck

halkar

There are few things you can check. You will need to go to your manifold. It could be under stairs.

Turn off all the thermostats except the room that is cold. Check the controller if the light comes on. If it doesn't then it could be thermostat wiring.

If you see light(s) on the controller check if flow meter left closed. These are usually at the top of the manifold with numbers on them indicating flow. If it's showing 0 or at the top there is no flow.

If there is no flow and flow meter opened (turn anti clock wise if not) check the actuator (if they are fitted) at the bottom of manifold. You can find which one by following the number on the controller light 1,2,3,4 etc. Usually there is a little red thing at the top raise when heat in demand. If it's not raised then it is probably not wired to controller properly or broken. If it's in raised form remove actuator by unscrewing from bottom of it and check the pin. These are similar to thermostatic valve. Pull the pin up as it may be stuck. Press it down with a plier and check if it's coming back.

If all above in order and working as expected it could be air in the pipe restricting water flow and pipe will need to be flushed. It's easy to do if you are DIY competent if not plumber can check. Some videos on YouTube on this.

timtim2016

Thanks a million. Had a guy from the company who installed out today, said he checked everything and couldn't find any issue. But the floor remains cold (noticeably colder than the same floor in the hallway beside it) and can't increase the temperature in the room even by 0.5c. I'll try what you have said above and then possibly flush the line just to check if it's not constricted anywhere.

John.G

You should have flow meters installed on each UFH loop they should read ~ 1.5 to 2LPM?. There may also be temperature gauges on the flow and return manifolds that should give a 5C to 8C difference (dT) in temperature.