Oven Problem

[barry1010]

My oven has a large knob which is rotated to turn it on, off and select different functions such as fan oven, grill, set programmes. When the oven is turned off the knob can be pushed in so that it is flush.
A minor fault has developed that you may have a solution for. The knob turns as easily as it ever did but it has become difficult to select the fan oven option. It simply does not change from 'grill' when I turn the knob. After some wiggling it works but keeps reverting to 'grill' during the cooking time.

The oven is probably 15 years old but has been no problem and I really don't want to replace it
Any ideas before I call in a professional?

[Redhelen72]

could there be some grease or dirt build up behind it making it difficult to select?
can you google the make and see if its a known issue?

[barry1010]

Good points, I will Google.

[TheWinner]

Don't click that link, its SPAM.