My whirlpool single oven isn't matching the temp on the digital display and not getting as hot as it should.

Eg I think it's on 200c but using an internal oven thermometer it only reads 160 and the hottest I can get when setting to full (250c) is about 200.

The fan works, so I guess it's either the thermostat / sensor or the element is a but dodgy?

Any ideas?

Gary Manning, December 2012