Just diagnosed mine with the same problems. I'm no electrician, but im fairly handy. PLEASE JUST BE CAREFUL, UNPLUG IT FROM THE MAINS BEFORE TRYING ANYTHING! Water and electric dont mix.
Couple of things you can check:
1) Remove the black hose that feeds the water tray at the top of the back panel and blow down it. If you hear bubbling, waters collecting in the tray at the bottom but not being pumped out, so its tripping the heater cutout/empty water indicator.
2) Again with the machine unplugged, lie the dryer on its back - you will probably see water trickle out. I left mine overnight, plugged it all back in and put a wet load in as a test and it dried fine. Couple of loads later, it went cold again.
Try the two checks above. If you get the same things happen as i did, check that the pumps working as described below.
At the back, down the bottom, is a small grey box. In here is the water pump that pushes water the the water tank, and heater cutout switch that activates the red indicator to tell you to empty the water tray.
I disconnected mine from the mains and opened this box. Then took out the section that holds the microswitch (the bit with the polystyrene attached to it) and the water pump. With this out and dry, i positioned it so i could see the pump blades without having to touch it. After making sure everything is dry to avoid electric shocks, i plugged the dryer back in and turned it on. Low and behold the dryer heats up, but the pump does NOT turn.
Completely removed the pump and tested it. Replacement pumps are about £30 inc postage, much cheaper than buying a new tumbler!!!!
Andy
November 2009