Gas hob trips RCD

1 May 2012
Reaction score
United Kingdom
I have recently had my flat rewired and settled in for a few months. Was randomly watching TV and the RCD tripped.

After switching all switches, RCDs and mains off, I turned the mains, and RCDs on and then each plug.

When I turned on the fuse connection unit for the gas hob, the RCD tripped. Its not the oven, that's on a separate RCD and spur socket. Checked it twice.

I called the electrician who wired the place and he tested the FCU and wiring. The copper looked fresh, insulation seemed OK and he replaced the FCU.

We did hear a spark type noise from the hob so he said its best to call Bosch out anyway while I'm under warranty.

Today, the RCD tripped again. It's definitely the hob even if I'm actually not using it. What could it be? The hob is 9 months old, was in storage for 3 months.

Moisture build up from storage/cleaning/spills?
Heating element already?
I was not using the hob when any of these trips happened.
Sponsored Links
Now if I went to a job where something was tripping the RCD I would test the item to see if that was the problem. As an electrician I have insulation tester and PAT tester and I would be very unlikely to leave without testing.

So I would hope the electrician had done the same and seeing under warranty went no further.

So why are you asking? If electric hob then maybe damp but there is no element in gas hob so only conclusion is it's faulty.
Sparker units on old gas hobs are often the cause of RCD trips - not sure which bit of the sparker unit causes the problem but it happens, but as I say that's usually old hobs, where something will have worn. If it's a newish hob then it's probably the same problem and you got a Friday afternoon product. But if it's under warranty, problem solved ....

Sponsored Links
Thanks. Lets see what Bosch say. When the hob was switched off at the FCU, I had no trips at all (about 10 days) as well. I noticed that the hob being ceramic, the burners are surrounded by ceramic squares, screwed onto the ceramic base. The griklls fit round those squares. Wandering if liquid gets in there. The first trip occured about 3h after boiling water on the hob, the 2nd 14h later after using the hob when the electrician was there.

Checked to see if the washing machine (next to hob) was leaking as trips occured when that was working. No sign of leaks along pipes and unit drains into the outside pipe. Also ran washing machine as normal in this 14h period after electrician visited with FCU to hob on and there was no trip then so seems unconnected.
Before I forget, can I use the hob with matches/a manual sparker in the interim, should I need to?
So Bosch came and could not id a fault but there was a small spillage which had got .in.Replaced 2 elex componants in hob and went. Let's see how we go.
Manufacturers' representatives often say there's nothing wrong, but then the problem disappears after they've been ... Sounds like the spillage may have left something bridging between connections to give you the tripping fault.


DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local

Sponsored Links