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.
Furnace blowing cold air on heat setting.
Furnaces use gas and heat pumps use electricity to generate heat.
Your thermostat settings need to be adjusted.
Your fan limit switch settings need to be adjusted.
Yeah that s a lot of possibilities.
A dirty air filter blocks airflow over the furnace s heat exchanger causing it to overheat.
For a heat pump or heater to produce warm air air must flow easily through the filter.
7 reasons your heater blows cold air ac blows hot air 1 dead batteries in thermostat.
If your furnace starts blowing warm but then quickly turns cold the flame sensor may need attention.
Change the air filter a dirty air filter restricts airflow into your furnace.
Well if your furnace is blowing cold air it s most likely due to one of these problems.
You have leaky air ducts.
So how do you know which problem is causing your furnace to blow cool air.
Gas is not being supplied to the unit.
Have an expert inspect your ducts along with the furnace.
Your thermostat is set to on the pilot light is out.
A furnace that is blowing cold air is most likely due to one of four possible causes.
Your furnace is overheating.
Seems silly but you d be surprised how often this has happened.
The thermostat is set to on if you notice your furnace is blowing hot air some of the time and cold the rest of the time your fan is most likely set to on when the.
What causes a furnace to blow cold air.
Your furnace may be blowing cold air because the filter is too dirty.
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.
When set to on the fan on your furnace will blow continually even when the furnace isn t actually heating the air.