2. Check the heater core hoses. The heater core hoses are responsible for circulating hot coolant from the engine to the heater core. If the heater core hoses are kinked or blocked, the heater core will not be able to circulate hot coolant and will not be able to heat the air.
3. Check the heater core. The heater core is a small radiator-like device that is located behind the dashboard. The heater core is responsible for transferring heat from the hot coolant to the air that is circulated through the heater ducts. If the heater core is clogged or damaged, it will not be able to transfer heat to the air and will not be able to heat the air.
