Check out
http://www.ukwhitegoods.co.uk/modules.php?name=Forums&file=viewtopic&t=13070&postdays=0&postorder=asc&highlight=zanussi+heater&start=0
There are 4 pages of info but the problem is solved on page 3 (pictures) where there is a dry joint on the pcb in the door, they resoldered this and all worked fine again. A few other posts have posted that it solved their problem of no heat or drying too....
Sorry to Fixed4free for linking to a competitor site but thought it may help your readers too.
Am about to try it tonight on my zanussi (thats if it is the same problem) Fingers Crossed.
PS. Please remove all power before opening the unit.
Chap1978, January 2008