* Low coolant level: Check the coolant level in the reservoir and add more if necessary. A low coolant level can cause the engine to overheat, which can in turn cause the heater to blow out cold air.
* Faulty thermostat: The thermostat is a valve that controls the flow of coolant to the engine. If the thermostat is stuck open, the engine will not be able to reach its proper operating temperature, which can cause the heater to blow out cold air.
* Faulty heater core: The heater core is a small radiator that heats the air that flows through the ventilation system. If the heater core is clogged or damaged, it will not be able to heat the air properly, which can cause the heater to blow out cold air.
* Faulty heater control valve: The heater control valve controls the flow of hot water to the heater core. If the heater control valve is stuck closed, the hot water will not be able to reach the heater core, which can cause the heater to blow out cold air.
* Faulty blower motor: The blower motor is what powers the fan that blows the air through the ventilation system. If the blower motor is not working properly, it will not be able to circulate the air, which can cause the heater to blow out cold air.
It is also possible that there is a combination of issues causing the heater to blow out cold air.
To troubleshoot the problem, it is recommended to take the vehicle to a qualified mechanic for diagnosis and repair.
