Apparently some driers have a reset button on the back of them which is needed if they have over-heated at all (there is an in-built trip that activiates if it senses overheating). Pull it out and have a good look around the back.
otherwise it could be the sensor, the thermostat or the heater element. It may be worth calling a "man who can" to see if it is worth trying to fix, a sensor is a few pounds on most machines whilst an element is nearly as much as a new machine.
Well I'm just giving the top a wipe and then I will shove it back into position and get DS's bedding dry! Erm...that sounds a bit much for me, thanks - quick once over with a J cloth is as much as I can manage
It is not my cup of tea either as it involves getting all the fluff out of the vent hose and so on but it is supposed to be fab in terms of extending the life of the drier and reducing drying itme - I am told it really is worth the effort.... I just havn't put in the effort to find out for myself yet
My washer dryer (with condenser dryer) had the same problem last week. It was going thru the motions of a drying cycle but not heating up. I've got a service plan with Hoover, and the bloke came out & replaced a faulty fan. It's been fine since.