1. Low coolant level: Check the coolant level in the reservoir. If it's low, add coolant and see if that resolves the problem.
2. Faulty blend door: The blend door is responsible for directing air from the heater core to the passenger compartment. If it's stuck or not working properly, it could prevent hot air from reaching the front of the vehicle.
3. Clogged heater core: The heater core is a small radiator that transfers heat from the engine coolant to the air that flows through the HVAC system. If the heater core is clogged, it will restrict the flow of hot air.
4. Stuck thermostat: The thermostat is a valve that controls the flow of coolant to the engine. If it's stuck in the closed position, it will prevent hot coolant from reaching the heater core.
