AC blowing hot or warm air? Want to figure out what the problem is before calling an air conditioning professional? This article is for you.
While there are many, many reasons your air conditioner is blowing hot air, we’ll run through the most common causes that you can fix or diagnose on your own.
The thermostat is set incorrectly
It may sound silly, but we’ve seen it happen before. Double-check your thermostat and make sure it isn’t set to “heat”. It may have been bumped by someone else in the home.
Also, check to see if you have your thermostat set to “auto” or “on”. If it’s set to “on”, that means the fan will blow even when the air conditioner isn’t actually cooling. This causes your AC to blow out warmer air out the vents when the outside unit isn’t running.
There’s a restriction in airflow
A restriction in the airflow to and from your air conditioner often results in not enough air coming out of the vents to cool your home. Restricted airflow can also cause the compressor (the part that moves the refrigerant) in your air conditioner’s outside unit to freeze up.
This is commonly a result of one or more of the following:
The air filter hasn’t been replaced in a long time
You haven’t had maintenance done on your AC this year (so the coils are dirty)
The outside unit isn’t getting electricity
Your air conditioning system is made up of two main components – an outdoor unit and an indoor unit. The indoor unit houses the fan that blows air through your home, but, long story short, it can only blow cool air if the outdoor unit is working.
So if air is blowing out of your vents but it’s not cold, it could be that the circuit breaker has tripped or the fuse has blown on the electrical circuit that provides electricity to your outdoor unit.
Check your circuit breaker or fuse panel to make sure the circuit is supplying electricity to the outside air conditioning unit.
Note: If the circuit breaker was tripped or fuse blown by the AC, you need to call a professional immediately as there could be a major problem.
Other causes
Most likely, if you’re having issues with your air conditioner blowing hot or warm air, it’s either a problem with the compressor/outside unit or your air conditioner is low on refrigerant. You may also have a return duct that is broken or disconnected and is pulling in unconditioned air from outside or an attic space. However, both of these issues require a professional’s help.