* Low coolant level: If the coolant level is low, the engine will not be able to circulate enough coolant through the heater core, causing it to blow out cold air. Check the coolant level and add more if necessary.
* Faulty thermostat: A faulty thermostat can prevent the engine from reaching its proper operating temperature, causing the heater to blow out cold air. Test the thermostat and replace it if necessary.
* Faulty water pump: A faulty water pump can prevent the coolant from circulating through the engine, causing it to overheat. Check the water pump and replace it if necessary.
* Blown head gasket: A blown head gasket can allow coolant to leak into the combustion chambers, causing the engine to overheat and the heater to blow out cold air. Check the head gasket and replace it if necessary.
If you are unable to identify and fix the problem yourself, it is best to take your car to a mechanic for diagnosis and repair.
