On the AVP site they claim that one problem with the Norcold and Dometic refrigerators is when traveling or parked at a site if the refrigerator is sitting off level the liquid inside the sealed unit does not flow correctly it pools in the other parts of the tubing causing high boiler tube temps and metal fatigue due to the high temps thus a leak and possible fire from the hydrogen. This control has a probe that attaches to the boiler tube if temps get above a set point on the controller it shuts off the refrigerator until temperature of boiler tube returns to normal.