Just in cased you haven't got the manual with you it states:
Are location and ventilation satisfactory?
Is the appliance level?
Is there a current in the wall socket and is the connection suitable for the appliance?
Is the mains power cable damaged?
For mains operation, is the electric thermostat swiched on? For gas operation, was the safety valve knob pressed down long enough?
Is the thermostat knob set towards the maximum position?
Is the gas cylinder or the pressure regulator valve open?
Is there any gas in the cylinder? (If by shaking, no liquid movement can be detected, then the cylinder is empty.)
Are by any chance two different power sources connected (such as gas or electricity)?
Was warm food placed in the unit?
Was a large quantity of food put in at one time?
Hope that helps, if not I can investigate further.
Hi Dan, my colleague has opted out so that I may be able to help you.
The fact you are saying you can feel heat coming from the back this proves the compressor is running, it sounds like a thermostat fault, as this would cause the issue on both gas and electric.
My suggestion would power it off and leave for a good hour, once the rear is no longer warm turn it back on using mains power, and leave it on 2 or 3, and ensure the lid remains closed for a hour, then place you hand inside and see if its starting to get cold.
If this doesnt work, you a very much limited to stripping the unit down and looking for a lose wire between the thermostat and the control knob.
No problem Dan, appreciate if you can please rate the service received so I may close the case.