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AC Troubleshooting: Why’s My Air Conditioner Blowing Warm Air?

AC Troubleshooting: Why’s My Air Conditioner Blowing Warm Air?

Is your air conditioner turning on but not blowing cold air? 

That’s a big problem. 

And if it’s the middle of a hot summer day, it can be an emergency. So we’ll keep this quick and to the point. 

Before you call an air conditioning repair company, check for these things that could be causing the problem.

Check your thermostat setting

If the fan is blowing, but the air seems warm or just not cool, check to see if your thermostat is set to “on” or “auto”. If it’s set to “on”, that means that the fan will stay on all the time, even when your air conditioner isn’t actually cooling your home.

This setting helps circulate air throughout your home, but can lead people to think that their AC is blowing warm air (and also use much more energy). Change your thermostat to “auto” if it’s currently set to “on” to avoid this.

Change your air filter

The air filter in your air conditioning system protects your air conditioner by removing large dirt particles and debris from the air. But if you leave the same filter in there too long, it gets filled with dirt and restricts the airflow to the air conditioner.

This can cause the condenser unit freeze up, keeping the AC from cooling your air.

We’ve also seen similar problems from “high-efficiency” air filters. Basically, these filters are designed to remove tiny airborne particles. But they also end up restricting the airflow to your AC, just like a dirty air filter does. Again, this causes the condenser to freeze so your AC can’t cool the air properly.

Take a look at your condenser (and maintenance records)

Another common cause of reduced cooling in home air conditioners is a dirty condenser unit. (That’s the outside part of your air conditioning system.) Buildup of dirt on the condenser coils (tubes that the refrigerant flows through) prevents your AC from properly cooling your air. The condenser coils need cleaning annually to maintain peak efficiency.

Also, weeds or bushes may be smothering the condenser unit and blocking airflow, keeping your AC from working properly. Cut things back until there’s at least two-feet (24") of space around the outside unit on all sides (including the top).

If your outside unit is really dirty, it’s probably been awhile since your last AC tune up/maintenance visit.

Call a professional AC company to get your air conditioner tuned up if that’s the case for you.

Other possible problems

These are just a few easy things you can check yourself to find the source of your air conditioning problem. If you’re still having issues, there could be any number of other problems, including:

● A faulty or broken condenser (the outside part of your air conditioner) 

● Low refrigerant charge/refrigerant leak

● A bad compressor

Get a qualified air conditioning professional to help you diagnose and fix these problems.

Minneapolis St. Paul Air Conditioning has been serving the needs of the Twin Cities areas since 1918.

Categories: Air Conditioning