APM 6115/6121/6125 Refrigerator Not Cooling Problem

Hi,

I’ve recently moved into a new house, and the refrigerator that was installed hasn’t stopped running since, the compressor is always on, it’s hot at the base, and it never goes below 6C (even with the door fully closed for hours, with the thermostat at any position 1 -> 5).

The seal on the door seems fine (no gaps), and there is plenty of ventilation for the grill at the base of the unit. The unit seems new so I can’t see anything obviously wrong with it.

I’d like to avoid an engineer visit if possible as working commitments keep me from being at home during the day, is there anything else I should check? or common reasons for the compressor running constantly without normal cooling.

The model numbers I have printed on the instruction booklet are :
APM 6115 / 6121 / 6125

There is no obvious manufacturer, but I suspect it’s linked to diplomat (?) since all the other appliances in the fitted kitchen are.

Thanks,
Mark.