When your car heater is blowing cold air instead of warm, it can be due to several reasons. Here are some common causes:
- Low Coolant Level: The heater in your car uses the heat from the engine’s coolant to warm the air. If the coolant level is low, there might not be enough hot coolant passing through the heater core to warm the air.
- Thermostat Issues: The thermostat regulates the temperature of the coolant. If it’s stuck open, the coolant might not get warm enough, leading to cold air from the heater.
- Heater Core Problems: The heater core is like a small radiator that transfers heat from the coolant to the air blown into the cabin. If it’s clogged or damaged, it can’t effectively heat the air.
- Air Trapped in the Cooling System: Sometimes air gets trapped in the cooling system, preventing the proper flow of coolant through the heater core.
- Faulty Heater Controls: The controls in the cabin, including knobs and switches, might be malfunctioning, leading to incorrect signals being sent to the heating system.
To resolve the issue, you might need to check and refill the coolant, replace the thermostat, flush or repair the heater core, bleed the cooling system to remove trapped air, or fix the heater controls. If you’re not comfortable doing these tasks yourself, it’s advisable to consult a professional mechanic.