it's more than likely that one of the thermostats has gone open circuit, unplug the appliance and remove the cover at the back of the appliance which covers the stats and the heating element, you should then see 2 stats one of them should have a coloured spot on it the other should be blank, if you need to replace the stats be sure to get that same coloured spot themostat as different coloured stats operate at different temps, they're very easy to replace like for like, you should'nt need an engineer as they'll charge a fortune for a 10 minute job you can do yourself. hope this helps. Good luck.
if you discover that one of the stats has a button on top just try pressing it as some dryers have resettable stats which simply cut-out when they overheat.
john
July 2007