faulty probe in under floor heating

[mikeF00]

Hi , the heating element in my under floor electric heating is in tact but the probe is faulty and as a result , the under floor heating doesn't work. Is there a way i could put another probe in without digging up the floor? Where is the recommended position for the probe with in the floor?
I was thinking of burying a new one under a tile on the floor directly down from control unit, therefore avoiding digging the floor up.

Perhaps there is another 'work around' i could try?

any help appreciated

Mike

 

[bobasd]

I dont know much about UFH period, and dislike both wet or elec types but for what its worth:

transfer this to elec forum.
Properly installed, most probes can be pulled out of their bit of flex conduit and replaced.
Sometimes, floor temps can be switched to a wall stat room temp.
The sparkies will know of the various tests to determine exactly what and where the fault is.

 

[Taylortwocities]

Test the resistance of the probe first. It should be around 12-15KΩ.

If it tests faulty, as @bobasd says, if it has been installed properly you should be able to slide the old one out through the handy tube that it is supposed to be installed in, and slip a new one in. The probe is supposed to be installed between a loop in the floor element. If you get it in the wrong place it is not going to detect the floor temp properly. Also it's going to be nigh impossible to remove a tile without damaging the floor element.

Also, as suggested above, if the controller is inside the bathroom, you could look at the menu and select room temperature (most controllers have a room sensor too). If its remote to the bathroom, you can fit an air probe like this in place of the floor probe.
http://heatmiser.com/brochures/thimble_sensor.pdf
It won't be as accurate as the floor probe, but better than chopping the floor about.

 

[ericmark]

Instructions for the floor I laid some 15 years ago said to use a pocket, i.e. a pipe which the probe fits into, with the idea it can be renewed, however it was found when I tried to renew the probe was stuck and could not be removed, the floor was in a wet room so nothing on the floor, so I tried running without the probe, I found that even on 24/7 the floor only reached 30°C and the limit is 27°C so I took a chance and ran it without a probe.

Today reychem underfloor heating does not need probes, the heating element is made so as it warms up the resistance increases, so is self regulating, only the cheap underfloor heating needs a probe, the problem with a probe is it only works where it is fitted, and the heating mat covers a very large area so it is of limited use anyway. It only really works with wet room or similar where there is never anything on the floor, when I fitted it in mothers wet room the reychem version was not enclosed in an earth braid so could not be used without laying an earth mat above it, so could not use it.

We found it was useless really anyway, once the floor had been dug out to put the insulation down and move drains, the floor was so well insulated even with the under floor heating off it never got cold, idea was to dry the floor, with heating on floor was dry after 2 hours if not mopped, and without it was dry in 2.5 hours, wanting a wet room at 22°C with a max floor temp of 27°C and a hall at 18°C with a bathroom extractor running it failed, had to have towel rail on to get room warm enough and switch fan on when leaving room not while having a shower.

The thermostat was just outside the wet room, so it really did need in theory some remote sensor, but found the heating was so useless anyway in practice worked OK without one.