Jointed cable behind walls to Indesit Oven

[meesh]

Not sure if anyone can give me any advice here. I've had no power supply to oven for 4 months. Had an extension to kitchen done about 3 years ago. About a year later had to get original part P electrician to come back and he said that a fuse had blown and that was why their was no power to oven. It then worked until now.

I've had two other NICEIC electricians test at consumer box and at oven switch above oven. Both are saying their is power at the consumer unit but this is not reaching oven. Original electrician jointed cable to oven behind the plaster. I have spoken with builder and he is saying that he will ask the original spark to come back but if it is fault that is not related to the jointing then he will charge me!! Is the fault likely to be at the cable joint? I have read on other forums that you should not joint a cooker supply.
This is a quote i've borrowed off a forum.

As an electrician, I would say this is a very bad practise. you should never joint a 45amp supply with a 32amp Joint box and you should never joint a cooker supply. I known it is expensive cable but just replace the whole cable it is the best and safest.

Any advice gratefully appreciated.

 

[Taylortwocities]

You can join cable if it is done correctly, however, a join in a cable can never be as reliable as the cable with no join.

You cannot join cable using screw terminals unless the junction is accessible for inspection in the event of a fault. Screw joins do loosen up over time and they are often the cause of failure in high-current applications (showers, cookers, etc).

If the join is to be buried/covered over/plastered/tiled, etc then the acceptable method is to use insulated butt crimps with the whole join being covered with heat shrink sleeving / self amalgamating tape.
Maintenance free connectors are also available but they need to be of the correct current rating.

So, let them dig out the join and see how it was done.