Underfloor heating Tripping RCD

[Doug99]

Hi All,

I have an electric underfloor heating system which is tripping the RCD when 'on load'. On initial power on, the control panel will illuminate ok and I'm able to set the temp +/-. But when I select 'H' the RCD will trip.

I have measured the screened 2 core cable going to the heating cable with the following:

Between 2 cores = 44 ohm
Between each core and screen = 23 ohm

Should the 23 ohm figure be more towards infinity?

Any advice would be appreciated - Thanks

 

[flameport]

Between the core and screen should be 10s of megohms at least.

23 indicates there is a short between the core and screen somewhere.
Essentially the heating element is ruined, replacement being the only option.

 

[Doug99]

Thanks for the quick response. I was fearing the worst as its fitted under a tiled bathroom floor.

 

[mikeyd]

The cables need specialist repair but there are companies who specialize in finding and repairing electric under floor heating. Obviously it will probably involve breaking at least one tile. You could try ringing the manufacturer and asking if they have any approved repairs local to you, or google under tile electric heating wire repair