You have already made a probable diagnosis - it's not getting hot - the thing that produces the heat - a heating element - is very likely defective.
There are other likely causes - the circuit that directs power to the element may have failed - the appliance may have an over-heat safety cut-out that could be defective - but...
When you get no heat then it's more than likely to be the heating element itself.
They suffer the thermal shock of heating and cooling - like light bulbs do - a common failure mode.
Your service engineer will be able to fix it for you.
Good Luck..., August 2016
