Heater Core: Description and Operation

The heater core (1) for the heating-A/C system is located in the HVAC housing, behind the instrument panel. It is a heat exchanger made of rows of tubes with fins. The heater core is positioned within the HVAC housing so that only the selected amount of air entering the HVAC housing passes through the heater core before it is distributed through the heating-A/C system ducts and outlets. The heater core tubes (2) are attached to the side of the heater core and are secured to the HVAC housing by a removable flange (3).

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

Engine coolant is circulated through the heater hoses to the heater core at all times. As the coolant flows through the heater core, heat is removed from the engine and 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-air door allows control of the heater output air temperature by regulating the amount of air 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.