As it sometimes works, would point to control pcb. If it was permanent, would point to heater element. Not sure about model. But could be a relay with dirty contacts, But not sure as to which relay, So look at all the relays, any that show signs of burn, discolouration of casing, You would need to, After unplugging, look at each relays contacts. If badly burnt, would need to be replaced, but slight, could clean with some fine wet/dry paper.
SD, December 2012