Chris at eSpares says...

Sounds like the thermostat. In order for us to answer your question or source the exact part you require please provide us with the following information: Appliance make, model and serial number of your appliance. For further help visit the "Finding Model Numbers" page on our website here: http://www.espares.co.uk/findingmodelnumbers. Alternatively please copy and paste this link into your web browser.