Car heater is working but blowing cold air. It also takes a long time to heat up. Frost is on the inside of windshield. What is the problem?
Dec 28, 2010 at 1:53 PM
MERLIN2021
✓Experienced Mechanic
17,250 POSTS
If both heater hoses comming from the heater core are hot, the blend door is NOT moving, if the inlet hose is hot but outlet is cold, the heater core needs more flushing, or replacement. if both hoses are cold, check antifreeze level and thermostat, also rarley but known to happen is the impeller blades on the water pump disolve over time and may not be pumping enough.