Can you post the model number of the appliance please?
Normally found when you take the warming drawer out.
Can you confirm that there is power getting to the appliance?
The Model is Cookmaster 100 CM 10 FR
I can confirm that poser is getting to the appliance as the grill is fully working.
This is a dual fuel appliance with LPG Gas burners and electric ovens, hot plate and grill.
We have had an electrician out to repair it but he cannot pinpoint the problem and we do not have a wiring diagram which might assist him.
I've put a link to the diagram for you.
It's a very simple circuit, one or both of the safety thermostats are likely to be open ciruit to give the fault you describe.
Click here for the wiring diagram
Hope this helps.