Reason Your Unit is Blowing Warm Air

DATE: April 28, 2017

Is your HVAC unit blowing warm air in the summer? Let’s investigate the reason your unit is blowing warm air today with, Comfort Talk with KCC. 

First things First: 

Turn off your thermostat!

A very plausible reason your unit is blowing warm air is due to frozen coils. The first step into investigating why you have frozen coils is to turn your thermostat setting to off. A thermostat is a device designed to regulate the temperature in your home. If the coils are frozen, the thermostat is sensing a temperature that is cooler than the temperature the thermostat is set for. The thermostat will then sense the need to blow warm air to maintain the temperature to which it is set. (are you confused yet?) 

Once the thermostat is off, check to see if the coils are frozen. If so, here are a few reasons this could be and what you can do to fix the problem:

Potential Reasons for coils freezing

Airflow is off
When airflow is off balance, the coils can drop below freezing. When this happens, the humidity in the air can collect on the coils and that will cause an even greater buildup of ice. Typically, this can be prevented by doing routine maintenance. Checking and changing out your air filter before the season can prevent improper airflow. If your filter is dirty or ill-fitted to your unit, the airflow can become off balance. Which, in turn, can prevent frozen coils.

Dirty coils & cooling fins
Once your thermostat has been shut off and the coils have begun to thaw, check to see if there is dirt in places other than the filter. If you find the coils and the cooling fins around the evaporator are dirty, these will need to be cleaned. Using a soft plastic brush with very little pressure is the best way to clean these. If too much pressure is applied, the fins may bend.

Refrigerant is low
If after you have checked your filter, coils, and cooling fins for debris and the problem persists, then the problem could be with the refrigerant. This is an issue that should be left to the professionals. If the unit is leaking refrigerant, the replacement must be performed by a licensed repair person.

It is important to remember that if your unit is blowing warm air and your coils are frozen to turn off the thermostat. Your compressor can burn out if it continues to run in this condition for too long. And, as always, if you don’t feel comfortable performing these tasks on your own, feel free to contact a professional.


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