Can any one help? I think the thermostat has gone on this oven as the fan element sometimes starts to heat up, but when the control knob is turned to select temperature setting the element cools down and then doesn’t heat up again, is this a fault with the element or the thermostat, if it is the thermostat is this easy to replace?
Sounds very much like a thermostat problem. Fiddly screwdriver job, not particularly difficult, however great care must be taken of the capillary tube when fitting.
Dave Conway will be able to help you with prices – some Comet own-brand spares a bit on the dearside.