There could be numerous reasons for this.
Removing the top cover of the machine reveals a long aluminium heater assembly, with various components attached.
There is a disc-shaped temperature sensor at the front, and two thermal cut-outs (thermostats) placed directly behind. Running a continuity check on these will possibly reveal that at least one of them is open circuit...these are normally to blame for malfunction. Behind these sit two sets of heater elements..again, these could also be faulty. After a stubby rectangular hose, there's also a fan, blowing the hot air into the drum. Check free movement here, both on the motor cooling blades outside, and inside the assembly. And worthy of note that if you live in a particularly hard water area, its also worth cleaning out the fill sensor tube, located lower down near the lower third of the drum.
Graham K, January 2014
