"a 5 year old fan oven that has had the fan replaced 3 times free of charge."
Don't remind me. It's coming up to that time of year again. One year the oven element blew on Christmas morning just after SWMBO had switched on to cook Christmas dinner. We've had at least one more element fail at about this time (not a real problem, I bought 2 after the first incident & keep ahead of that game now) and also a fan motor. At least it's a 15 year old oven so not as bad as yours.