It could be that the thermal device on the heating element has tripped. IT CAN BE RESET with a bit of know-how, but first.
*** THIS POSTING IS BASED ENTIRELY ON MY OWN EXPERIENCE AND NO GUARANTEE IS MADE OR LIABILITY ACCEPTED HERE. BY ALL MEANS USE THIS POST, BUT DO SO ENTIRELY AT YOUR OWN RISK, OR GET A PAID PROFESSIONAL IN ***
Secondly, I suggest you get a plug in mains monitor from Maplin ( http://www.maplin.co.uk/module.aspx?moduleno=38343 ) - might seem excessive but it's a great diagnostic tool for aound the house so you'll find other uses for it. Set it to watts mode, plug your dryer into it and start attempting to dry a load of wet clothes. If the watts displayed doesn't go above a few hundred then the heating element isn't getting any power. (Should see ~1800 or ~3000 when heaters go on).
Okay. IF the heaters aren't coming on, then the thermal cut-out has most likely tripped. Here's how to reset it:-
*** UNPLUG FROM MAINS ***
Not just protecting myself legally here. I'm pretty comfortable working with live electrics but I managed a short which destroyed my meter and my underwear!
Remove the back cover (many many screws) and you will see the element unit. There are two temperature devices fixed to it. Verify with a meter that the lower unit has tripped by confirming an open circuit across it's terminals before going any further.
This lower unit is meant to be a one-time device, and when it trips you are supposed to fit a complete replacement heater element assembly (mucho dinero). However...
If you remove the heater assembly you should notice that the lower device has a little dimple or plug/seal on it's back - Now, using that Dremel you bought yourself for xmas and the smallest drill bit you can find (about the size of a toothpick), very gently drill out the dimple little by little until you're through. Then, ensuring that the dryer is NOT plugged in and listening carefully, gently insert a toothpick (or something of similar size) into the hole and press - there will be a barely audible click. The device has now been successfully reset! Check with a meter.
Refitting (as we all know Haynes says) is reverse of removal.
Now the bad news.
When this trips, it's usually not the problem but merely a symptom of something else and you'll find that it trips out again fairly soon. In my case the relays fitted to the controller board were sticking and so the heaters were left powered ON even though the controller had commanded them OFF - hence overheat - hence trip.
I'll explain how to change the relays in another post.
TumbleDownMonty
February 2009