Fitted a new control module ( on the advice of engineer) to my fridge/freezer but previuos problem still persists. After fully defosting and fitting new module appears to work fine. Freezer stabilises at -22C and fridge set to +4C. Using remote thermometer to check- some 24 hrs later Freezer drops to -30 then both fridge and freezer suffer temp rise, out of control. Don’t think evaporator defrost system working (no water in eavporating tray) Couldn’t find defrost stat so assumed it must be part of control module? How do I check eg evaporater heater or stat and where are they on this machine?