Heater Core: Description and Operation

Heater Core - Typical:

The heater core is mounted in the HVAC housing, located behind the instrument panel. The heater core is a heat exchanger made of rows of tubes and fins. The heater core inlet and outlet tubes are integral to the heater core and cannot be serviced separately.

The heater core can be serviced by removing the HVAC housing from the vehicle.

Engine coolant is circulated through the heater hoses and heater core at all times. As the coolant flows through the heater core, heat removed from the engine is transferred to the heater core fins and tubes. Air directed through the heater core picks up the heat from the heater core fins. The blend door allows control of the heater output air temperature by regulating the amount of air that is flowing through the heater core within the HVAC housing. The blower motor speed controls the volume of air flowing through the HVAC housing.

The heater core cannot be repaired and, if faulty or damaged, it must be replaced.