I have a Liebherr K3660 larder fridge that is ~18 months old. It has suddenly started running much too cold (around -4 C). I have tried adjusting the thermostat and also defrosted the fridge. After defrosting it ran fine for a couple of days maintaining a temp. of 4 C but now it has started overcooling again.
Any ideas on the most likely cause? I guess a faulty thermostat is most likely but I am wondering if there could be some other reason.
Thanks.