The top oven has stopped heating to the required temperature. It seems too heat until it is slightly warm when the fan option is enabled. The top oven is the smaller of the two and has less options with fan being the only "proper" option to cook. This seems too have happened within the last week. It is built in so hasn't been moved and hasn't been cleaned. We inherited after buying the house and have the manual but no idea as to how old it is.

Kitchen Ranges - Rangemaster - 90D Range