no heat from tumble drier zanussi tde 4234?

the program starts as requested, stops also, forward and reverse action working also ,door switch working but no heat from heater elements , but there is power to it but heater elements dont get hot (mate touched it while it was running and got a shock of the coils in heater element the wally) all lights working and low heat and buzzer working just no heat ? all heater coils look intact and all terminal`s from power supplyare still connected to coil ends! any sugestions what is wrong ???