If the thermal over temp went I would check and make sure the flue is clear and the baffle is in place and the upper chimney area is clear not squirrel nest or birds nests pull the top cover and look down from the top. If you have fans you should be able to see them. With that said when testing an RV fridge it is normally done on AC to ensure you are getting a constant temp. It may take a couple of days for it come down in temp. Inspect the boiler area for signs of yellow powder if you see any no matter how small your unit is leaking and needs to be repaired. I put an amish unit in my coach.