Abstract: An HVAC unit for a recreational vehicle includes an enclosure having an ambient air inlet, an exterior outlet, a return air duct connection, and a conditioned air duct connection. An air conditioning system and a heating system are each located within the enclosure. The air conditioning system includes a compressor, a condenser, an expansion device, and an evaporator operably connected for cooling air entering the enclosure through the return air duct connection. The heating system includes a gas-fired burner assembly located within a sealed combustion chamber and a heat exchanger operably connected to the combustion chamber for heating air entering the enclosure through the a return air duct connection. A control system is operably connected to the air conditioning system and the heating system to selectively heat or cool air entering the enclosure through the a return air duct connection and exiting through the conditioned air duct connection.