Electric underfloor heating

[Darrellpope]

I have installed underfloor heating to my lounge and the tiles after a couple of months have started to have air line cracks ?
When I installed them the main floor was floo boards so I installed 3/4 plyboard sheets across the whole room and fixed down ,I then painted the floor with heat reflective paint as described in the underfloor heating manual that came with the kit.
I installed the wire element to the exact spacing details in the manual and then used flexible adhesive which sas its compatable with underfloor heating I then laid the tiles and used flexible grout to finish the job.
I waited a few days before turning the heating on , the sensor for the heating is in the floor as described in the manaul.
All worked well until a few weeks ago approximately 3 months after the tiles have started to have air one cracks ? The heating still works perfect but we have stopped using the heated floor so no more tiles crack.
Is there a solution for this or some thing have done wrong ? and when I replace the tiles I assume I will end up breaking the heater wire getting the broken tiles up ?
Any advice would be appreciated thanks.

 

[mattysupra]

i feel sorry for you!. Another person that has realised how crap this system is. Saying that i may be jumping in to soon. Is this secondary heat sorce run a t maybe 18c or a main heat source run at 25c +

May i ask what you heating bills are like now compared to before?


As for your problem. It can be caused by a few things.

1- to much flex in the subfloor?
2- Running to hot or reducing temp and raising temp to much (3c per day?)
3- Incorrect air flow under the floors. Air bricks blocked or lack of air bricks
4- plywood not acclimatised, way to dry maybe or way to wet before it was installed?