What is the primary function of a heater core in a vehicle's heating system?

The primary function of a heater core in a vehicle's heating system is to act as a radiator for the heating system. When the engine of a vehicle runs, it generates heat. This heat is transferred to the coolant that circulates through the engine, and as the hot coolant flows into the heater core, it releases this heat into the vehicle's cabin.

The heater core is essentially a small radiator that allows warm air to be blown into the passenger compartment, thus providing a comfortable temperature inside the vehicle during colder conditions. The core's design with fins and tubes maximizes the surface area for heat exchange, making it efficient in transferring heat.

In contrast, generating heat is something that occurs in the engine rather than the heater core itself. Circulating cool air is the role of the vehicle's air conditioning system, and while the heater core requires proper air flow, it does not remove air from the heating system.