Could anybody please advise Whirlpool fan oven Mod no g2p91r/wh with a main oven thermostat fault . When you switch the fan oven on and select oven temp it all warms up and you think it is all OK .After a short while the digitall temp readout drops and then cuts out.You can hear hear teh relays cutting in and out. Could it be a sensor fault or is the controll pcb in need of replacement. Many thanks.