Under Floor Heating Floor Temp Question

[Lewis's Friend]

Hi all, I was hoping for some advice on running an underfloor heating system.

We have just had a wet system installed in our extension, and it is controlled by a ProWarm thermostat. The thermostat only measures air temp, and does not have a floor temp probe.

The flooring is an Amtico LVT finish, which has a maximum floor temp of 27degC. I can adjust the water temp in the manifold, but this may not be exactly the same as the floor temp.

Can I simply use a thermal camera on the floor and then tweak up the manifold temperature until I have the floor temp where I would like it to be (but under 27)? Is it that simple? I assume it should be, but would hate to ruin the flooring!

Thanks

[Rough101]

You’d need a black bulb thermostat looking at the floor to control that, but first I’d get a cheap infra red thermometer and see how hot it gets before the space sensor closes the valve, although the water might be in the 40’s, it’s unlikely that the floor goes above 25, as it’s constantly losing heat to the air above.

The last time we had it installed, the contractor was more concerned about the bi folds and floor to ceiling windows.

[Sheepshanks]

What happens when the sun shines on it?

[Lewis's Friend]

Thanks for the reply.

Unfortunately putting a probe in the floor at this point would be a bit of a nightmare. An oversight on my part.

However, I can borrow a good Fluke thermal camera which although only accurate to +/-2degC, should allow me to understand the relationship between manifold temp and floor temp, and thus not overheat the Amtico.

That's my theory anyway.

[OldPal]

You’ll be fine using the thermal camera, what you want to make sure of is that you raise the temp slowly if it has just been laid. We recommend about 1c a day up until your desired temp. If not it can potentially blow the screed off the floor and that is just a disaster. Also make sure your fitter used high temp glue other wise it will shrink and fail over time.

Edited by OldPal on Monday 10th February 21:06

[Arrivalist]

This might be a silly question, but why are you fussed about the floor temp?

I’ve got UFH throughout my house and all I set is the desired room temp and let the heating system do the rest.

As I missing something?

[Arrivalist]

Okay, on reading about this, I can see that with some floor finishes. This might be a really useful thing to have.

[Lewis's Friend]

Thanks for the replies.

The UFH actually started up by itself at top heat while I was out (the thermostat was not linked or setup at this stage) - happily no damage done to the latex 'screed'.

After turning the water temp right down I'm now slowly increasing it again until it is warm enough to hold 20degC air temp and I'm monitoring the floor temp with the thermal camera. This may well be overkill...

The only downside so far is the camera is too good and can clearly read the pipe temp as opposed to the rest of the floor temp! I have looked at where a floor probe would normally be installed, and this is equidistant between the pipes so I assume this is a good place to take a reading from with the camera.

[Lewis's Friend]

OldPal said:

You’ll be fine using the thermal camera, what you want to make sure of is that you raise the temp slowly if it has just been laid. We recommend about 1c a day up until your desired temp. If not it can potentially blow the screed off the floor and that is just a disaster. Also make sure your fitter used high temp glue other wise it will shrink and fail over time.

Edited by OldPal on Monday 10th February 21:06

Thanks for the advice, that's very helpful.