Heater Blowing Cold Air

One possible cause is an air lock in the cooling system.

Heater blowing cold air. There could be various reasons for car heater not working but it basically happens for two reasons. The thermocouple is a sensor that controls the gas valve and ignition. Another common problem is when air gets into the cooling system. If you do manage to relight the pilot but it keeps going out a faulty thermocouple is likely causing your furnace to blow cold air.

7 reasons your heater blows cold air ac blows hot air 1 dead batteries in thermostat. Run the engine until the fan kicks in. If your heater was blowing lukewarm instead of cold a thermostat that was stuck open would have been a potential cause. Once your fan has come on look around the radiator for a bleed port or bleed screw.

When overheating your furnace can trip a high limit switch causing the furnace burners to shut off so that the heat exchanger does not crack. Is your heater blowing cold air right after you turn it on. During the winter when you crank up your heat the coolant is brought over from the engine to the heater core that then blows warm air into your car. 2 clogged air filter.

This is usually a simple fix but you ll need to call a technician to adjust or replace it. It can feel cool for the first few minutes because the engine has to warm up in order for the coolant to heat up and provide heat to your interior. A furnace blowing cold air could be due to your thermostat. Air from the blower is not blow toward the heater core or the coolant does not flow through the heater core.

A dirty air filter blocks airflow over the furnace s heat exchanger causing it to overheat. A c ar heater blowing cold air could be a symptom of the failure of the heating unit. Due to their design heat pumps blow colder air than gas and electric furnaces. Check the furnace s air filter your furnace may be blowing cold air because the filter is too dirty.

Seems silly but you d be surprised how often this has happened. For a heat pump or heater to produce warm air air must flow easily through the filter. If your system has a bleed port or bleed screw and you can find it you can fix this air lock yourself. Furnace troubleshooting from asm.

Again using occam s razor we can assume that. I have found that occam s razor works more. Since the heater core is often the high point in a cooling system air can move into it and become trapped.