Hansberger Refrigeration Blog: Your AC Repair Resource

Why Is Your AC Only Blowing Warm Air Into Your House?

It’s a moment we all dread, especially in our hot climate: The air conditioner is blowing warm air. What to do about it? Should you call your HVAC consultant right away, or are there a couple of things you can troubleshoot? Let’s have a look so you can get cool air blowing ASAP.

  1. Check the air filter. When was the last time you checked your air filter? Go on. Have a look. Dirty? You’ve been running the AC for many, many weeks without a change — what do you expect? A dirty air filter impedes airflow, slowing it down so the AC doesn’t cool properly. Change your filter regularly, especially in the hot summer when the AC is running all the time or if you have smokers or shedding pets in the house.
  2. Have a look at the evaporator coils. Dirty evaporator coils can keep the AC from properly cooling the air in your home. Find the evaporator coils inside the interior side of your HVAC unit. Spray them with a solution made specifically for coils or with household detergent and water. Use a special evaporator coil brush to clean them. Spray afterward with a self-rinsing evaporator coil oil. This cleans the coil and will rinse off during the cooling process as moisture from the home evaporates on the coil. But a better method is to schedule a visit from your HVAC pro and have them clean the coils.
  3. The compressor is malfunctioning. You’ll have to call the HVAC pro on this one. Some of the signs: shuddering and shaking when the compressor comes on; clicking, ticking, or rattling coming from the compressor; the outdoor unit overheats; there’s liquid on the ground by the compressor; and of course, there’s warm air coming out of the vents.
  4. Refrigerant is leaking. Besides the fact that your AC is blowing warm air, you may hear a hissing sound or find ice on the evaporator coils. Refrigerant can be recharged, but the leak should also be fixed.

For more on why warm air is coming from your vents, contact Hansberger Refrigeration and Electric Company.