diagnosing oven fault

Hi all,

We've inherited a house here very close to the coast here in L'Ametlla de Mar which we're looking to sell once we've got all the paperwork and services straight.

We got started with Iberdrola with the basic/lowest electric plan.
The house was rewired in 2004 when this kitchen and oven were fitted and the fuse box was all professionally installed.
When I use the oven (either with or without the fan) and am not using any other electrical devices in the property (fridge off aswell) then after several minutes a 40A circuit breaker fuse in the fusebox trips. The cooker has it's own double fuse but this doesn't trip.
When I run only the washing machine and the water heater and the fridge (I'm trying to deliberately overload my supply) then the trip on the meter box outside trips. Nothing inside in the fuse box trips. All these items work fine on their own.
Therefore I'm assuming that the oven is not over loading my supply but that there's a fault with the oven as it's tripping the wrong fuse for a load issue.
Does that make sense?
We would only occassionaly use the oven anyway so I don't want to pay to upgrade the supply if the fault is with the oven.

Thanks in advance,

Richard

If you have a 40A fuse in your box then you are contracted for 9.2Kw which is more than ample to run all the household goods. Most have 5.75Kw fitted nowadays and 25A with no problem. We can run the oven and most other things at the same time with our 5.75. A domestic electric oven should use around 1.5Kw but no more than 3.5Kw even if you have one of these fancy double ones with a few add ons. 

I would suggest you have a fault with the oven wiring so should get an electrician to look at it. Certainly don't need upping your contracted power as you have more than sufficient.