Help UFH floor sensor routing, how?

[mattwaddy]

So i've got my plans back from Wunda and about to start laying in the next week, however I need to install a floor sensor to measure and restrict maximum floor temp to preserve flooring correctly.

This is what I'd be installing https://heatmisershop.co.uk/remote-sensor-probe-3m/

Now the layouts in each route are snail pattern and so I'd need to run this over the existing routes somehow, I see some people encase theirs in a section of pipe, but worry that if I run another 16mm pipe over the top of the existing ones to get towards the center of the room the build up might be too high? I can't route in the insulation layer unless I route a section out first before putting down a slip layer perhaps, but pushing the membrane into that won't be easy. Thoughts? What did you do?

 

[roguetrader]

Doesn't need to be in the centre of the room.
Only needs to come out from the wall 300-400mm.

 

[Madrab]

Is it a wunda overlay system? it just need to be located in the middle of 2 pipe legs usually along the edge of a room so it can run under one of the pipe legs as it won't really be walked on

 

[ericmark]

I made a mistake, the pocket has too steep of a curve, and when I came to replace it, it got stuck, but does not really need to be central. Just a reasonable sample of heat, I would have preferred to have used Raychem heating mat, which does not need it, but then it needed an earth mat over it.

It was in a wet room, and proved useless, took too long to heat up, and re-heat after water cooled the tiles.

Put me off UFH for life, lucky had heated towel rail.

 

[mattwaddy]

Is it a wunda overlay system? it just need to be located in the middle of 2 pipe legs usually along the edge of a room so it can run under one of the pipe legs as it won't really be walked on

no wet underfloor heating part of structural floor

 

[Madrab]

no wet underfloor heating part of structural floor

OK, so it's UFH in a screed? The reason I ask is that wunda do an overlay panel that the wet UFH pipework sits in.

So no it doesn't need to be set into the centre of the floor or anywhere specific, as suggested anywhere that will allow the sensor to detect the generalise/mean floor temp.

 

[robinbanks]

Is this zone running at a different temperature to the others?

 

[robinbanks]

was in a wet room, and proved useless, took too long to heat up, and re-heat after water cooled the tiles.

Put me off UFH for life

Sounds like the timer wasn't coming on early enough before you needed to use the room, but then UFH is best suited to running constantly at a low level in a well insulated house.

Totally don't understand the water cooling thing; the only water that hits my 26 degree UFH'd tiles is 40 degree shower water, so it actually heats them up..

Funny how differences arise; I personally think UFH is amazing and wouldn't ever have anything else

 

[ericmark]

Mine was electric, don't understand why it needs a sensor with wet, you set the temperature of circulating water?

As to my mothers electric, idea was to dry wet room floor so not slippy, and as a second function warm the room, I did expect the power shower to heat rather than cool floor, but this was not the case, and it would take 20 minutes to feel any heat, and 2 hours to get really warm.

However before fitting the UFH the floor was dug out and a good 6 inches of insulation put in, so even with UFH off the floor was much warmer than other tiled floors in the house.

With heating on floors dried in 40 minutes and with it off 45 minutes, so not really worth using, as to heating the room, the extractor fan removed more than floor put in, and replacement air from hall at 17 to 18 degs C, so relied on the large towel rail to heat room.

 

[mattwaddy]

Wunda have advised me to run a small channel in the screed once set so the sensor is in contact with the flooring rather than bury in the screeded layer.

 

[robinbanks]

Floating a bit of pipe, wood etc in your screed (that you pull out when it sets) is easier and less risky than grinding it out after

But why are you using a temp sensor on this zone anyway?

 

[mattwaddy]

Floating a bit of pipe, wood etc in your screed (that you pull out when it sets) is easier and less risky than grinding it out after

But why are you using a temp sensor on this zone anyway?

So the lvt im planning for all rooms downstairs has a maximum floor temp of 27 degrees, hence needing to guarantee the floor doesn't get hotter than that. With it been flow screed Im not sure I'll be able to float something in it as I won't be installing it

 

[robinbanks]

Anything less dense than the screed will float on it, trust me - if needs be you can visit site in your wellies on screed day and have a stomp around in it before they settle it

I still don't understand the sensor though; your UFH will(should) flow from a manifold that has a TMV on it; that's what sets the flow to (e.g.) 27 degrees, not some sensor that cycles the flow on and off.

If you're heating the screed with a heat pump then you can just ask it to produce 27 degree water, and forget the TMV (but if you're having UFH upstairs and it's carpeted then your flow temp might need to be higher for heat to bully its way through the carpet, so you're back to using a TMV downstairs)

I've a 40mm poured screed on 150mm PIR and karndean downstairs, do have UFH pipes upstairs but don't bother to use them; the upstairs runs a few degrees cooler than the downstairs. If I had the time over again I wouldn't have put 300mm of acoustic wool in the ceilings, nor would I have bothered with fitting UFH pipes to the upstairs at all

 

[SpecialK]

Would 27 degree water take ages to heat the slab? I pump mine through at 40 with click LVT. Slab goes over 27 degrees. No issues yet.

 

[robinbanks]

Would 27 degree water take ages to heat the slab?

UFH isn't something you blast on and off like rads..