Hi I've got fridge/freezer Whirlpool. Hi I've got fridge/freezer Whirlpool ARC7470. The fridge

Question

Hi I've got fridge/freezer Whirlpool ARC7470. The fridge stopped working despite the freezer being ok. If I want to make it work a have to turn the thermostat wheel to "off" (even the fridge light goes off) and turn it back. Than it works for a few hours and stops again. The thermostat isn't bimetal type it looks like rheostat Thanks for help