What is a heater core?

A heater core is a component of a vehicle's heating and cooling system that provides heat to the interior of the vehicle. It is typically made of copper or aluminum tubing that is wrapped in thin fins to increase the surface area for heat transfer. Coolant from the engine flows through the heater core, and the heat from the coolant is transferred to the air blowing over the fins. The heated air is then blown into the interior of the vehicle through the vents, providing warmth for the occupants on cold days. Some common problems with heater cores include leaks, clogs, and corrosion, which can cause reduced heat output or a sweet smell inside the vehicle from leaking coolant. In some cases, a failed or leaking heater core may need to be replaced.