Underfloor heating

saving123

hi we have recently moved house and the underfloor heating in the bathroom isn't working. We thought it was the thermostat so bought a new one but an electrician fitted it today and although the thermostat now appears to be working the underfloor heating isn't. The bathroom is fully tiled (floors and walls) so I am wondering if there is likely to be a way of finding out whats wrong without ruining the tiles! Thanks in advance

Tothepoint.

Did the electrician do any tests?

saving123

he said he thought it was the thermostat initially but wasn't 100%

Tothepoint.

Best get him back to test it or someone who knows what they're doing.

missile

Tothepoint. wrote: »

Best get him back to test it or someone who knows what they're doing.

Best get someone else, preferably with experience of fitting / repairing heating.

You may be able to claim from the seller? Have you asked your solicitor?

spadoosh

saving123 wrote: »

he said he thought it was the thermostat initially but wasn't 100%

Hes not a very good electrician. Literally all you need to do is put a multimeter on the two wires coming from the mat and check resistance. You can buy a multimeter yourself and test it for about £4. Any break in the matting would show up. Suppose the difficult bit is knowing how big the matting is to know the right resistance reading. Have you got any packaging instructions for the UFH?

Providing of course it is electric UFH and not a wet system.

somethingcorporate

Have you tried turning it up really high?

When we had ours fitted we initially thought it wasn't working - it was, it just needed to get very hot before you could feel it through the tiles.

Ainsley1

Might just need a bit of time to warm up the floor? If it is turned up highish say 25 degrees C then you should then feel it.

But I would agree with the adverse comments about the leccy! No think about it. All the components can be easily tested (as has been posted). Even if the correct resistance of the heating pad is unknown he could have at least checked that current was flowing when the stat was 'on'. Very poor service.

Kiran

If you establish that there is a break in the cable you need a time domain reflectometer (TDR) to establish how far along the cable the damage is. It is still a bit of guess work though unless you know what arrangement the UFH went down

JohnB47

There is another possibility and that is that the sensor is faulty. It's just possible that it is sending a permanent 'hot enough' indication to the Timer/Thermostat.


The sensor is a small electronic device, about the size of a paracetamol capsule, fitted on the end of a fairly stiff lead. This goes from the back of the Thermostat and should be fed through a length of flexible pipe, under the tiles. The pipe allows you to withdraw the sensor lead and replace it with another.


We had UFH fitted a few years ago but after a month or so I noticed that after it was on for a while, the temperature reading fluctuated wildly, one second saying it was 9 degrees, then 30, then 12 etc. Turned out it was the sensor. I replaced it myself but first had to break into a stud wall to find and expose the flexible pipe that the installer had trapped in a piece of the stud woodwork. He was a right chump - why go to the bother of fitting the pipe and then trap it making it impossible to withdraw the sensor!


Your electrician should be able to test the sensor as well as the UF wiring. Not sure what the sensor should read but others might know.