Sometime prior to going O/C Elements go out of shape and the Fan (assuming its a fan oven) strats fouling on the element, causing all sorts of noises.
Try taking the cover off for a better look.
Just to add, the insulation itself is hygroscopic.
Which means, it isn't just a case of moisture getting in to the insulation; once a hole is made, the insulation will actively absorb any moisture!
Yep, quite true - which was why I suggested it would absorb moisture through the hole. It is the same insulation as used in mineral insulated cables, sometimes known as Pyro. Open ends of the cable have to be temporarily sealed to prevent the absorption, then sealed permanently when installed.
Engineer just been, the noise is the large cooling fan. The small oven thermostat doesn't work either so the cooker was overheating too. The mains trip was down to the large oven grill element going short. He said it was due to the large oven never being used and it absorbs moisture over time and when it is used it shorts out.
If you need to find a tradesperson to get your job done, please try our local search below,
or if you are doing it yourself you can find suppliers local to you.
Select the supplier or trade you require, enter your location to begin your search.
Please select a service and enter a location to continue...
Are you a trade or supplier? You can create your listing free at DIYnot Local