Oven keeps tripping RCD

mustard.

Our oven keeps tripping our RCD after being turned on for 30mins (or so). I'm not 100% sure if it's tripping out randomly, when the oven's hot, or when the oven reaches temperature and the thermostat turns off the element, though it appears to be the latter. I've replaced the element in case this was causing some leakage, however this hasn't worked

Is there anything else I can/should try before I'm forced to buy a new oven?

The RCD/consumer unit was fitted a year ago and we had all the circuits tested then, we had no trouble with the oven until last week so I assume it's not a faulty RCD.

Cheers!

Mr.Generous

What's the rating of the circuit breaker supplying the cooker?
Is it a dedicated circuit I.E. not part of a ring main.
What's the rating of the oven in watts?
You'd be surprised at how long a breaker will run over capacity before it trips, 30 mins sounds about right. Quite a few ovens now too powerful for a 13 amp plug, even single ovens.
Is the hob electric and on the same circuit too?

mustard.

It's an 80A/30mA RCD.
The oven's has it's own circuit (with the electric hob), though the RCD also protects a couple of other circuits in the house (each with their own MCB).
The oven is 1700 watts.
The hob's on the same circuit but often isn't on when the RCD trips.

I don't want to buy a new oven only to find the problem's not the oven at all!!!

Thanks for your help!!

Aylesbury_Duck

I experienced this a couple of months ago. I pulled the oven out after isolating the power to it and at the point where the power cable is connected to the terminal box was a scorched plastic connector box, the smell of burnt plastic and burnt insulation on the neutral cable. A loose connection was causing intermittent arcing which had burned the insulation away and tripped the circuit breaker.

The cable had plenty of excess on it and the terminals themselves were undamaged so it was possible to fit a new plastic housing, strip back to new copper on all three cables and refit to the terminals securely. It's worked perfectly ever since. I pulled the oven out again just before Christmas to clean behind it and was able to check that all was well.

Ms_Chocaholic

This happened several months ago to our oven, tripping the RCD after about 20 or so minutes after we switched it on. We had fitted a replacement heater coil but it wasn't a manufacturer produced part we had used, when we replaced it it was fine.

Mr.Generous

Sorry I'd assumed it was tripping the mcb - if the rcd is tripping there is a leak to earth, check the wiring and then the element.