1 thermostat is set to on is your furnace blowing cold air only sometimes.
Furnace blowing cold air no heat.
Seems silly but you d be surprised how often this has happened.
Your furnace may be blowing cold air because the filter is too dirty.
Other causes of furnaces blowing cold air pilot light ignition problem.
For a heat pump or heater to produce warm air air must flow easily through the filter.
Is the furnace s blower constantly running.
After ruling out all of the simple problems above the most likely cause of a furnace not blowing air is a problem with the blower fan itself which if you remember is the fan that circulates your house s air over the heated coils.
2 clogged air filter.
Most furnaces also have a reset button that clears any issues that might cause the furnace to produce no 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.
To troubleshoot a misbehaving gas furnace start with the easiest explanations and solutions then work your way to the most complicated.
If your gas furnace is blowing cold air a number of factors could be to blame many of which you can address on your own without the immediate help of a service professional.
Have an expert inspect your ducts along with the furnace.
Otherwise your electric heater or gas furnace will not turn on.
Or the gas line isn t supplying enough gas to your furnace.
Ensure that your thermostat is set higher than the temperature in your home.
3 pilot light is out if your gas furnace is only.
If your furnace seems to be blowing cold air it could be a problem with the ignition.
Again using occam s razor we can assume that the next likely culprit for your heater blowing cold air is your thermostat.
Set the thermostat to heat and.
If you haven t been regularly checking and changing your air filter it s most likely extremely clogged.
A furnace blowing cold air could be due to your thermostat.
Check the thermostat and ensure it is set properly.
A dirty air filter blocks airflow over the furnace s heat exchanger causing it to overheat.
Your gas supply could be turned off.
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.
You might not think your filter contributes to your ac not blowing cold air but it does.