We've had ours trip out a couple of times due to fluff in the condenser, you need to clean this out every few months, take it out and use a hosepipe to get the fluff out, also make sure where the filter sits is free of fluff (I used a screwdriver to scrape it all out).
Anyway, to reset the heat sensor:
- Unplug the machine
- Take off the rear heater cover (large teardrop shaped metal panel on the rear)
- Unscrew the heating element so you can see the back of the two sensors
- One of the sensors has a small hole, put a pin or something through the hole and you'll hear a click. it's now reset.
- Reassemble carefully and test.
It's a pretty crappy machine...
Jeff
January 2011