cooker trips RCD breaker

[david123456789]

If I turn on my electric oven after about 5mins or so the RCD that the cooker is connected to trips.
It first happened after some heavy use, the oven had been on for maybe 6 hours (pizza party) and the breaker tripped, causing a fairly abrupt end to the party. I noticed at the time even the metal front panel of the oven had become hot to touch. (overheating melting some wires or something?) Now whenever I turn on the oven the RCD trips after about 5 mins.
The oven is a Lamona built in oven probably just over a year old (just out of warranty) and hadn't been used too much before last weekend's incident.
I tried the grill (in the same oven) and it trips the breaker too.

Any ideas what could be causing this? I phoned up an electrician to see if they could look at it but they said it wasn't worth them coming round as its most likely a problem with the oven.

I had a look around the forums, but I don't think its the element as other people with that problem seem to trip the breaker instantly. Am I wrong?

 

[PrenticeBoyofDerry]

It could still be the element.
Turn your oven on then when it it trips, reset the RCD and turn oven back on and see if it trips quicker!
The lamona are a Howden range check that it's not 2 year warranty!
Depending what model you have, they could have a two elements for the oven top and bottom try them individually.

 

[david123456789]

It trips instantly once it has tripped once.
It's a one year warranty.
Its a built in single fan oven, HJA 3300.

I got a repair guy round and he said it was likely an earth leakage problem. He thought it was the element. He took some measurements with a multimeter and said there was a problem with the oven element. I think he was measuring for continuity between the element and the case (i.e. earth).

When i said the same problem occurred when i used the grill (in the same oven) he said that might be faulty too. Took some readings off that to the case, but wasn't consistent, sometimes open circuit sometimes a high resistance.

He said he'd need to change both elements. Phoned me later to say the repair would cost £160. I checked on google to see how much a replacement oven would be. £130 off ebay (new). So i said no thanks to the repair.

Went and ordered 2 new elements off the net and replaced both myself. Just installed them, plugged in the oven and............. same problem.
Any ideas?

cheers, david.

 

[chivers67]

Think you've got to start looking further back if both elements have been changed. What are the cable/conections like in the isolation switch?

BTW how many Pizzas did you cook!

 

[bernardgreen]

Does the oven have a fan that circulates air around the door and casing to keep the door cool ? If it does and the door is getting hotter than normal then the fault might be in the fan motor.