Strange problem with hob / RCD - would really appreciate some advice.

[TanDiy]

Hi, I wonder if I could trouble those in the know for some help please.

A few weeks ago the RCD tripped. I find this is due to the hob or cooker. Both are connected to the same circuit which has the usual red switch on the wall. If I turn the wall switch off then the RCD resets fine. Immediately I turn the wall switch on, the RCD trips again. Disconnected the hob and the RCD stayed on, so suspect hob is the issue. Reconnected the hob and the RCD reset and has been working for the past few weeks. Suspected there must have been a bad connection which was now ok.

Today the RCD is tripping again, I pulled the hob out and laid it on the side so that I can get to the wires. Before doing anything further I checked that the RCD was still tripping when I turned the wall switch on. Disconnected the live wire to the hob and the RCD is now happy. Reconnected the live connection to the hob and the RCD is still happy. Everything now up and running again.

The connections to the hob all appear fine, I would expect the RCD to start tripping again when I reconnect the hob? It was consistently tripping every time I turned the switch on. Disconnect / reconnect and it works again? Would appreciate any advice. Thanks

 

[mwatsonxx]

Seems you have an intermittent fault on the hob. Next time it happens make a note of which plates were in use.

 

[TanDiy]

Thanks for the info. It did not trip when it was on. It tripped about 2 hours after it was used.

I pull the hob out and lay it upside down on the work surface and turn on the cooker switch - every time the RCD trips immediately the switch goes on. I disconnect and reconnect the live wire and it works ok again. I wonder why disconnecting and reconnecting clears the fault. I am thinking that I probably need to get a new hob. Thanks for your help

 

[mwatsonxx]

As its after use, that would point to liquid leaking into the hob, inspect the surface and edges, make sure it is well sealed. Also the area where the cable connects and the cable connections.

 

[ban-all-sheds]

What sort of hob is it?

 

[TanDiy]

What sort of hob is it?

John Lewis JLBICH605 Ceramic Hob - I think it has halogen rings (bright orange).

Thanks