Hi everyone.
I am visiting a job tomorrow where the client's UFH thermostat broke in March 2014 causing the heating and tiles to get very hot. The stat was replaced in March and all was apparently well until July 2015 when the grouting started to crack. Unfortunately I have no information on the type of UFH system used or substrate/tiles etc. but bearing in mind the time span, does this sound like it could be the fault of the overheating system or more likely due to some other defect? Any suggestions would be much appreciated.
Cheers
Hi Robb,
You could do with finding out what brand heating it is, and if the thermostat is a digital or standard one. If they replaced the thermostat, did they replace the thermostats probe too, or just the actual controller?
Electric underfloor heating cable once encased in adhesive or self levelling compound shouldn't really get hot. And if the stat or the probe fails, or even both, meaning the cable had a direct feed with no control, it would still only heat up to a certain temperature and not really damage anything per se. It'd just have no control.
I would assume that the cable is faulty. Or it has been installed with a lot of air pockets perhaps (maybe dot and dabbed? - which might explain the stat failing twice in a short time period maybe).
It shouldn't at all cause the floor to expand so much that it cracks adhesive or tile.
We spend a lot of time finding the cause of an issue on this forum and it's often wasted time. That heating system needs condemning, checking by an electrician (who is clued up with electric UFH and can use the right testing equipment), and then really, it either needs not ever using again and they keep the tiled floor as is, or repairing if you can find the faulty spot (if it is just one area and just fault cable somewhere, and not dot and dabbed on the whole floor in which case it'll all be faulty now) and perhaps retiling in that area and / or the whole floor if it's all faulty.
www.electriciansforums.co.uk is one of our sister forums, the largest electrical and electricians advice website in Europe, over 52,000 electricians on there. Feel free to register and post on there. Say Dan has sent you from tilersforums.com. Perhaps ask them what they'd do. I don't mind posting if you can't be arsed to register. I'll link you to the thread so you can read the response. But they'd probably ask you for info to be fair.
Sounds like something beyond the stat is wrong.
And I can't see you standing on the floor, looking at it, working it out. It needs testing really for a break in the cable, and checking the continuity of the cable, the stat probe, and then perhaps the thermostat its self testing.
It isn't a tilers job though mate.
