Underfloor heating thermostats

Gavin John Hyde · Oct 16, 2018

I tend to run a mile from underfloor heating as its a pain in the backside to put right if it goes wrong.
Got a regular customer whose old manual thermostat has died, power goes to it, but nothing else, its dead. Tested resistance of the heat mat and the values pretty much same as paperwork when installed.
Being a basic manual one, from my limited UFH experience then any other manual one should work? after all it only has Live and Neutral from supply, CPC terminates on back. then live out to mat, neutral out to mat, with 2 wires for the sensor down through conduit.
Anybody got any thoughts?
pic shows current one. I shall be hoping to replace with another one of same ilk. albeit newer.

[ElectriciansForums.net] Underfloor heating thermostats

SparkyChick · Oct 16, 2018

I can't say for certain as I don't have much experience with UFH, but I suspect the temperature sensing element and the thermostat itself may need to be matched.

There are a few methods of sensing temperature electronically, some purely resistive (like thermistors - which have different temperature curves and values) and some semiconductor based which operate in an entirely different way.

Gavin John Hyde · Oct 16, 2018

SparkyChick said:
I can't say for certain as I don't have much experience with UFH, but I suspect the temperature sensing element and the thermostat itself may need to be matched.

There are a few methods of sensing temperature electronically, some purely resistive (like thermistors - which have different temperature curves and values) and some semiconductor based which operate in an entirely different way.

I think that is why a lot of the thermostats available come with the probe/thermal sensor aswell, to ensure compatibility. It relies on the original install to have installed a conduit or pipe run to be able to slide it down or into the floor..
Electrically speaking it is straight forward, just a nightmare to fix as it can mean ripping the floor up!

telectrix · Oct 16, 2018

or buy a stat that is capable of sensing room temp. this would normally be set lower than you'd expect as ufh is generally to keep your tootsies warm, not heat a room.

buzzlightyear · Oct 16, 2018

tell your customer by a desent pair of slippers if it can't be fixed.

telectrix · Oct 16, 2018

you're slipping buzz.your normal post spelling would have said "kippers".

.

Octopus · Oct 16, 2018

You can still buy them like that ......

Octopus · Oct 16, 2018

Murdoch said:
You can still buy them like that ......

this one

Warmup MTC Thermostat | Topps Tiles - https://www.toppstiles.co.uk/tprod248/warmup-mtc-thermostat.html

And I would normally bypass the controller to make 100% sure that the underfloor matt still works!

Gavin John Hyde · Oct 16, 2018

Murdoch said:
this one

Warmup MTC Thermostat | Topps Tiles - https://www.toppstiles.co.uk/tprod248/warmup-mtc-thermostat.html

And I would normally bypass the controller to make 100% sure that the underfloor matt still works!

Yes i did clock that model, but topps are a bit pricey! believe it or not the con artists known as CEF have same model branded in Heatstore logo for £42.00 inc of vat which for CEF is one of the rare bargains.