Furnace Blowing Cold Air On Heat Setting

The furnace has overheated.

Furnace blowing cold air on heat setting.

You have leaky air ducts. Your thermostat settings need to be adjusted. A dirty air filter blocks airflow over the furnace s heat exchanger causing it to overheat. Have an expert inspect your ducts along with the furnace.

7 reasons your heater blows cold air ac blows hot air 1 dead batteries in thermostat. Furnaces use gas and heat pumps use electricity to generate heat. 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. Your thermostat is set to on the pilot light is out.

So how do you know which problem is causing your furnace to blow cool air. Your furnace may be blowing cold air because the filter is too dirty. Your furnace blowing cold air could be caused by hot air escaping through holes in the duct work that carries the heat throughout your building. What causes a furnace to blow cold air.

Change the air filter a dirty air filter restricts airflow into your furnace. For a heat pump or heater to produce warm air air must flow easily through the filter. A furnace that is blowing cold air is most likely due to one of four possible causes. Well if your furnace is blowing cold air it s most likely due to one of these problems.

Seems silly but you d be surprised how often this has happened. Yeah that s a lot of possibilities. Gas is not being supplied to the unit. So if you feel the air blowing out of the vents while the furnace is off the air will seem cool since it ll be at about room temperature.

2 clogged air filter. Your fan limit switch settings need to be adjusted. When set to on the fan on your furnace will blow continually even when the furnace isn t actually heating the air.