Ufh Cable Might Be Damaged.

[Sean Kelly]

Thanks Mr Purdy. I think you are right. I only just nicked the plastic coating of the cable to expose a bit of the metal earth. I would have checked the resistance but when I unscrewed the thermostat there was no play on the cables. All I saw was 3 mats connected. There was no way I was going to unscrew the wires and test them, i'd never get them back again!

 

[dynamictiling]

Even if the cable has snapped it can be fixed. Ever warm do a joining kit for it. Get a spark to do it obviously. My spark took £70, takes roughly 3 hours.

Hardest part of it is trying to get a decent spark who is willing to undertake the task in hand

 

[Stef]

I carried out my own repair, shrink tubbing from Maplin so no moisture gets into it.
It was only the outer earth I exposed also.

 

[Marvo]

You'd need to continuity test the heating wire and the outer earth wire if there is one then you'd need to insulation test the wire using a 1000v mega tester. You might need to get a bit creative to mega test the insulation if the heater doesn't have an earth wire running inside it, the damaged area would need to be exposed.

Problem with heat shrink tubing is you'd need to cut the wire completely to get it on then rejoin afterwards.

If you damage UFH wires my best advice would be to get a sparky in who specialises or has lots of experience with UFH systems. This especially goes with UFH in a bathroom which is far more likely to give people a fatal shock if it's faulty.

 

[Stef]

I phoned the company I buy my Mats from & they put me on to the technical man from Ireland where the Mats are made & he talked me through it.
The mat is still going strong after 3-4 years.

 

[dynamictiling]

You'd need to continuity test the heating wire and the outer earth wire if there is one then you'd need to insulation test the wire using a 1000v mega tester. You might need to get a bit creative to mega test the insulation if the heater doesn't have an earth wire running inside it, the damaged area would need to be exposed.

Problem with heat shrink tubing is you'd need to cut the wire completely to get it on then rejoin afterwards.

If you damage UFH wires my best advice would be to get a sparky in who specialises or has lots of experience with UFH systems. This especially goes with UFH in a bathroom which is far more likely to give people a fatal shock if it's faulty.

If the rcd detected any irregularities it would trip the power. If there is anything problems with the ufh, this is far more likely to happen than someone meeting a shocking death (no pun intended) ufh controllers also monitor this and again will trip the power if there is a problem. It is highly unlikely for anyone to get an electric shock from ufh.

Even older fuse box's are likely to trip with irregular currents from ufh running through them.

 

[Marvo]

RCD's save lives but there's no guarantee, some people die from shocks of less that 30mA, it's just a numbers game where most will survive but some won't.

Older fuse boxes often don't have RCD protection, only overload protection. The fuses in them only protect the circuits from overload damage, they don't protect people from getting fatal shocks.

All the UFH controllers I've experienced are just a temperature control, they don't include shock protection or earth leakage protection. Technology progresses and systems are constantly made safer so I'd be interested to read up on the controllers you refer to if you can give me a link.

People getting shocks in a bathroom are far more likely to be killed than in other locations. The electrical regs recognize this and address it by declaring bathrooms 'special locations' that require extra protection measures.

It probably is statistically unlikely to get a shock from an undamaged UFH system as you say but if the wire is damaged under the floor and there's moisture around the damaged area it's highly likely it would cause someone in bare feet to get a shock. There's many variables involved so it might just be an occasional tingling or 'static' sensation when touching taps or a towel rail or it might be worse.

My advice still stands, if the UFH heater tape or wire is damaged I'd strongly advise an official repair by someone with experience who can test the system afterwards.