The last time this happened to mine, it was the main thermostat that was permanently open circuit. (part no TY9285020). This thermostat is marked NC60, so I am guessing it is normally closed (NC) until 60 deg.
As for as I remember, it cost around £25 for a new one. Fitting was fairly easy - screwed or clipped into the plastic ducting under the drum - two wires connected with spade connectors.
John Bailey, April 2007
