Posted on 9/26/2025
You start the car on a freezing morning, turn up the heater, and wait. Instead of warm air, cold air keeps blowing through the vents. Aside from being uncomfortable, this kind of issue points to a problem under the hood. If the heating system isn’t working when you need it most, there’s a good chance something in the engine’s cooling system isn’t doing its job. How the Heater Is Supposed to Work Your vehicle generates heat as a natural byproduct of engine operation. The heater core, a small radiator tucked behind the dashboard, uses hot coolant from the engine to warm the air that blows into the cabin. A fan pushes that warm air through the vents once the engine reaches a proper temperature. If the heater core doesn’t get enough hot coolant or if airflow is restricted, you’ll feel little or no heat at all. Low Coolant Can Disrupt Heat Flow One of the most common reasons for cold air from the heater is low coolan ... read more