FIRST unplug appliance you need to open the back small panel you will see two closed thermostat supplying current to the element, to test disconnect each thermostat, connect two plug in each and start the appliance in the highest setting. if this is to work then it either one or both of the thermostat are in the open position not not delivering the current to the element. (if it still giving cold air then its your element) replace thermostat (cost only a couple of pounds).
puzzled ????
anjumzaman13@hotmail.co.uk glad to help.
domestic engineer
anjum zaman
October 2007