Faulty electric underfloor heating testing :(

[bugs183]

So at last one of my worst nightmares has come true, i have a faulty u'f'h mat.
The floor is concrete, then marmox 6mm boarding. Two electric under floor heating mats, both resistance and continuity tested by myself and the electician whilst rolled up. Now i always put testers on, and i use a tester on each mat as i lay the mat and level. The electrician, connected both mats together and told me it would work ok off one sensor. I couldn't see how but he told me it was fine. Floor was levelled, everything seemed ok, tiled the floor, everything seemed ok.
Now i can't remember doing a final continuity test before i left the job on each mat. Being a bit of a worrier and a realist, not an optimist, i'm 95% certain i would have tested both mats independantly, but i'm only human, so i can't say for certain.
The electrician wired it up at a later date, felt the floor warm up, and thought everything was fine, but it wasn't he didn't check to see if the other area was warming up
Now i'm not here to blame anyone, i just need some help, and to also lead by my own mistakes. If you have two mats always use two testers, test at every stage possible, and if at all possible have the electrician double check too. Sounds like common sense, but i've done lots of these and it's easy to be complacent.

I've heard that through thermal imaging the area where the fault is can be found, does anyone know of a specialist that can do this in the Gloucs area?
Any help would be greatly appreciated.
JB.

 

[Gazzer]

Try this John Repair Service - Underfloor Heating Repairs

 

[Dan]

Two mats can be added to one stat fine providing the load doesn't go over what the stat is capable of (you can normally get about 18sqm out of one I think if it's about 150W per meter mat - might be wrong might be less but you can do it - sparky would have checked that).

Obviously a repair kit is needed here, but after you locate the damage.

If both mats are not working it would suggest perhaps the stat is a fault though maybe?

Can you confirm that both mats are dead? Nip back and do another test on them both independently to be sure. As your problem might be the stat and that's dead easy to fix / replace.

It's normally strange (and very unlucky) to have both mats die on you at the same time.

Not sure on the thermal imaging thing but I have heard of that so you should find the specialist you're looking for. Hang on for a few more to reply as I'm sure we have a few people that have needed to use such a specialist before now.

 

[Dan]

Neale beat me to it then.

 

[bugs183]

Hi chaps, ta for the prompt replies!!!!
As said the larger mat has been working fine, but the smaller mat has never worked.
I've had the whole mats disconnected from the controller and one of the mats is showing a fault, so it's not the stat or the controller, its the mat itself that is at fault. Yep it is rare for two to go, and it usually is the stat that is at fault.
I use Underfloor Heating Store, and they've given me a chap to phone, but i'm gonna try Sir Ramics guys and see how that goes. Ta!
I've (luckily?), been feeling rough today, so bailed work at breakfast to come home, so i've been searching thew net for answer and solutions. It appears that with a thermal imaging camera you can trace the short in the cable due to the spark, so you can get to within a tile of where the problem is (this is what i have read anyway). I'm not too stressed at the mo, just thought i may as well use this minor catastrophe to help everyone here not make the same mistake.
Why did i listen to an Electrician????????

 

[bugs183]

To add to this lesson learned situation. Here's what i will be doing from now on, i guess many of you do already, sorry if it appears i'm telling you how to suck eggs!.
I would recommend that for every job you do take full details of each mat you use. Manufacturer, mat size, wattage resitance, and take photo during installation, and when using multiple mat label fully which mat is which at the tail end connections, to avoid confusion.
Always use a seperate tester for each mat.
I love hindsite!

 

[Gazzer]

I presume you have looked for the obvious such as a dumbo carpenter screwing a doorstop to the floor which has just happened on one of my jobs ? At least I know where the break is.

 

[philipb]

Hi there,
If you got the heating mat from a reputable source it will have a manufacturers warranty on it.
Contact them and they should send an engineer with the proper tester to locate the
fault.If it is a fault with the matt then they will stand the cost,if it is caused by something
you have done wrong,then you will have to pay the cost.

 

[Uheat - Keith]

We have in our records: Steve Ashby of Ample Heat Limited and Michiel Bester, both Southern England.


Lot of good information on this Thread.

As Dan says, Control of more than one Mat or Cable can be with two or more joined together in PARALLEL in a low level service box. Box on the wall etc, not in the floor.
15amp controller can switch upto 3400w. 16amp controller can switch up to 3600w.

If the tests on the mats was good before being laid, cable must have been caught while installing/covering with compounds.

Always a good idea to test about 4 times. 1. While mat in box. 2. After taking mat out of box. 3. While installing or when finished installing. 4. After compound have covered mats.

 

[bugs183]

Ta everyone, i've phoned a few people, but had no luck, but i'll keep you posted.

 

[bugs183]

Spoken to Steve Ashbury, he's been recommended by two different compnies so i'm going with him to help with the problem.

 

[DHTiling]

Let us know how it goes..

 

[RogertheBodger]

Any news yet? got me interested in this!

 

[bugs183]

Hiya Roger Bodger.
I've got Steve booked in for early August, he's a busy man, and the client has been very good about it all so they don't mind waiting.
I'll let you all know.