Water heater appliance freeze prevention in recreational vehicles

A water heater appliance for a recreational vehicle, the water heater appliance defining a vertical direction, a lateral direction, and a transverse direction, the vertical, lateral, and transverse directions mutually perpendicular, the water heater appliance comprising:

• a cabinet;
• a heat exchanger positioned within the cabinet, the heat exchanger comprising a first temperature sensor;
• a combustion chamber positioned within the cabinet, the combustion chamber comprising a burner assembly, the combustion chamber in thermal communication with the heat exchanger;
• an inlet coupled to the cabinet, the inlet comprising an inlet tube fluidly coupled to the heat exchanger, the inlet tube comprising an inlet temperature sensor;
• and
• an outlet coupled to the cabinet, the outlet comprising an outlet tube fluidly coupled to the heat exchanger, the outlet tube comprising an outlet temperature sensor and an outlet heater.