Servis M7455 fridge freezer not cooling properly

Hi – I would appreciate some help….

My Servis M7455 fridge freezer is 18 months old and recently food has started thawing in the freezer compartment although it was quite frosted up towards the top of the freezer compartment, so I manually defrosted the machine.

It then started up and began cooling fine for a few hours but then stops. I can only get it cooling again by turning the power off for a couple of hours and then back on – it then restarts immediately (compressor hums and pipes at back get warm) but switches off after a few hours and will not come back on, even if I leave the fridge door open – again I can only get it to restart by switching the power off for a couple of hours then restarting.

It was situated in a lean-to at the back of the house and I wondered if it was the cold weather resulting in it malfunctioning, but I have brought it indoors and the same thing is happening.

Having read a few posts, I am guessing could it be the compressor relay, thermostat or overload protector that has gone??

All advice gratefully received – thanks