Air Quality | TIPS AND TRICKS PT. 3

Air Quality | TIPS AND TRICKS PT. 3

Air Quality |Tip 13. Steam coming from outdoor unit
A. We hear this complaint mostly from new heat pump owners at the beginning of each heating season. Sometimes they think it is smoke and that their outdoor fan motor burned-up because when this is happening the motor actually stops running.

Don’t worry, this is a good thing! This is your unit during the “Defrost Mode”. It happens regularly during the heating season. The outdoor coils tend to frost or ice-up during the winter. This causes the unit to loose efficiency. By regularly defrosting itself, the heat pump runs more efficiently.

When the unit goes into defrost, a couple of things happen. First, the outdoor fan motor stops running. This helps build-up more heat to melt the ice. Also the reversing valve shifts from the heating mode to the air conditioning mode. That’s right, you are actually running the air conditioner. By making the outdoor unit the condenser, the hot freon gas passing through the coils accomplishes the defrosting. Lastly, the supplemental heat is energized to offset the now, cold air blowing in the house.

Yes, it does sound a little bizarre to run the air conditioning and back-up heat at the same time during the winter. But it usually only happens for a few minutes at a time and only when needed.

Now, this should only happen periodically except for severe weather conditions (snow, rain, sleet). If your unit is constantly going into defrost, this indicates a problem.


  • Outdoor coil blocked – possibly with leaves

REMEMBER, when in doubt, call a certified, qualified air conditioning service technician. -blackjack air




Air Quality control operates 24 hours a day, always ready to assist you with any cooling needs you may have. We are a family owned AC Repair Service company and offer a Comprehensive AC Repair Service in St. Petersburg and surrounding areas!

For more information and tips contact your trusted AC service company – Air Quality Control at 727-469-3832