Underfloor Heating

[chloebear]

Hi all,
I have a client with electic underfloor heating (two mats) one is fine the other shows an open circuit - anyone know how I can locate the break in the cable without digging up the whole floor?

 

[Mr Brady]

@chloebear
Assuming you've started by looking for fixings into the floor and checked them for signs of stray voltage, if the mat is not buried too deep, then you could try with a "live cable detector" preferably one with adjustable sensitivity.

Start by putting a supply to one side of the mat, if it's not shorting out then it should present mains voltage at the open end, then try the other side to either confirm it or show up more than one break.
Be safe! well insulated shoes and gloves! or better still use the 110v side of a site transformer that way you are isolated from the mains.

 

[ashrow]

You have no chance. there is a way to work out the distance of a fault if you know the approx run of a cable but to find the location of a fault on a heat mat would require more luck then skill (heat mats have elements that run back and forth so you would need to know which way they run and the distance they are spaced to even come close to the point of the break)....Sorry but taking up the tiles is the only option i can offer. Others may know a way!!!!!

Ash

 

[steamboatwilly]

Yeah, agree with ashrow....this isn't a straight run of cable but is likely to be a closely twisted run.

Assuming the mat worked at some previous point there must have been an incident to cause the break? Grandmother and eggs I know but have you looked around for any broken tiles or grout (indicating a tile has moved) or something fixed down (floor) or up (ceiling)?

The better news is that many mat manufacturers provide a repair kit once you've found the blighter.

 

[Spudnik]

There are special tracer tools available but where and how much im not sure.

A search on the net may bring some results.

 

[Dave]

Were the mats tested prior to tiling..? who did these tests..?..

 

[eco]

Entry point is main fault.

 

[plug444]

The cable is in effect a heating element and cannot be repaired. Your only chance would be if the fault is in the tails connected to the mat. This is one of the big problems with electric under floor heating which is why most big jobs use wet systems.

 

[Lou7]

It can be repaired if you can find it, they sell repair kits which is just a through crimp and some heatshrink sleeving.

 

[plug444]

It can be repaired if you can find it, they sell repair kits which is just a through crimp and some heatshrink sleeving.

Just done a search and you are indeed correct so I stand corrected.

 

[Lou7]

No worries, I wasn't digging you out.