Underfloor Heating Drilled Through!?!

[Deleted member 9648]

Get the fitter back DONT Pay him and possibly charge him for the refitting,retiling renewing the heating mat as I dont think thede can be "repaired" as such

Read post 8 !!

 

[Deleted member 9648]

The UFH cable has an earthed screen and damage will cause an earth fault which will trip an RCD.
Only way is an insulation test @500v to establish whether the cable is sound.

 

[peterc2609]

Mate just tested it. Reckons neutral has been shorted to the earth.

What does he do on the insulation test?

a screw through a 3mm cable... madness!

 

[Mr Mike]

Have you had the whole bathroom area fitted with under floor heating.
If you have, did you inform your bath room fitter of the same.

 

[Deleted member 9648]

Mate just tested it. Reckons neutral has been shorted to the earth.

What does he do on the insulation test?

a screw through a 3mm cable... madness!

A multimeter wont be much use,you need a 500v insulation tester,and test between the live core and the earthed screen of the cable..you should expect a reading of hundreds of megohms if the cable is sound...<1 megohm would be a worry....if damaged you may get a dead short,ie 0.00 megohms. If the IR is OK test the continuity of the cable using your multimeter....the reading will be in ohms and should match the manufacturers declared resistance for the legnth/rating cable you have.

 

[Mark_Burgess]

Have you had the whole bathroom area fitted with under floor heating.
If you have, did you inform your bath room fitter of the same.

He mentioned it in posts 7/8.

All you can do with the floor is rip it up and start again.

 

[GLENNSPARK]

Mate just tested it. Reckons neutral has been shorted to the earth.

What does he do on the insulation test?

a screw through a 3mm cable... madness!

Post 2

 

[Mr Mike]

He mentioned it in posts 7/8.
Yes Mark he did, I missed that.
Underfloor heating needs to be treated with kid gloves. Check the resistance after un-packing and after each and
every operation/activity to completion.

 

[peterc2609]

Gold star to GLENNSPARK.

Can it be repaired? I'm seeing differing opinion?

 

[peterc2609]

I'm guessing the insulation test wont be much use now.... especially if the neutral is shorted to the earth.

Does that simply point to a screw through the cable?

 

[GLENNSPARK]

If the fault wasn’t there before said fitter arrived how can it be a borrowed neutral?

The only reason i mentioned the borrowed neutral was i asked if he had a recent board change.........

 

[Deleted member 9648]

Did your mate test the cable completely disconnected??....if not you will get a N-E reading if the N is still connected.
If you are using a multimeter to find a fault you are likely to get misled....a high voltage insulation resistance test is still essential before ripping it all up...there's no way I would be relying on a multimeter.

 

[GLENNSPARK]

I'm guessing the insulation test wont be much use now.... especially if the neutral is shorted to the earth.

Does that simply point to a screw through the cable?

If the screw (metal) is providing a fault path between both conductors then...yes

 

[peterc2609]

Yeah cable was totally disconnected.

Looks like a screw, I'll have to remove toilet, tile and repair.

 

[Deleted member 9648]

If the screw (metal) is providing a fault path between both conductors then...yes

The cable is a single conductor,it is likely unless the cable is completely broken that you would get a reading on both the live and neutral ends,which is why I ask if the cable was completely disconnected before the test.