Why your AC unit is not cooling the house

When temperatures begin to climb across Wilmington, North Carolina – and air conditioners are being pushed to the limit – they do tend to break down and need to be repaired.

The cooling pros at Hadi Heating and Air are here to answer common questions related to this issue, shining a light on why an air conditioning system suddenly blows warm air. Our HVAC technicians also share some troubleshooting steps homeowners can take to fix minor system problems, avoiding the wait and expense of a service call.

Some of the most common reasons ACs blow warm air are:

  • Dirty air filter
  • Frozen evaporator coil
  • Thermostat settings errors
  • Lack of electricity to the outside unit 
  • Refrigerant leak

Dirty Air Filters

When the cooling system’s filter is dirty, the air conditioner cannot properly move air through the system. This issue strains your air conditioner and can cause an AC to blow warm air.

When determining what’s wrong when your AC isn’t properly cooling your home, first check your air filter to ensure it is clean. If the existing air filter is dirty, replace it with a new, clean filter to see if the warm air issue resolves.

Frozen Evaporator Coils

Your air conditioner’s evaporator coils extract heat from the home’s air to start the cooling process. A bi-product of this process is condensation, which is why air conditioners have a drip pan and condensate drain to catch the extracted moisture and move it out of the system. When moisture collects on the evaporator coils, they may freeze. Frozen coils prevent heat transfer, so you’ll feel warm air blowing from your AC system if this problem is present. 

Check for this issue by shutting off power to your air conditioning system and opening the access door to interior system components, which allows you to assess the evaporator coils. If you see frost or ice on the coils, the best option is to give the coils time to thaw – this can take up to 24 hours depending on the severity of the freeze. Leave your air conditioner off and do not run it again until the coils have thawed.

Frozen evaporator coils can be caused by poor airflow, refrigerant leaks, system damage, or other issues. The root of the issue must be resolved to prevent a recurring problem.

Thermostat Settings Errors

Sometimes, a simple mistake at the thermostat can lead to an AC not providing enough cold air. If the blower fan is set to ON instead of AUTO, it runs all the time – not just during a cooling cycle. In between cooling cycles, the air you feel from the vents can be warm.

Check your thermostat’s settings if you have an AC that’s blowing hot air. Ensure the fan is set to AUTO and the COOL setting is selected.

Lack of Electricity 

In a split air conditioning system, both the indoor and outdoor components must run to complete cooling cycles and deliver cooling in the home. If power supply to your home’s outdoor unit is interrupted, the indoor components are the only ones working, which causes warm air to blow from the home’s vents.

Ensure your outdoor unit has power. Check the home’s electrical panel to verify the breaker has not tripped; reset it if needed. Also, check the ON/OFF switch on or near the outdoor AC unit to verify it is set to ON. 

Refrigerant Leaks

Refrigerant leaks are also a reason why your AC blows might be blowing hot air. When refrigerant escapes the system via a leak, the air conditioner doesn’t have the proper charge to complete its cooling cycles. Thus, the air you feel indoors is warmer than it should be.

Refrigerant leaks must be corrected by a licensed HVAC technician with the proper certifications for refrigerant handling. 

When Your AC is Blowing Warm Air, Call Hadi Heating and Air in Wilmington!

When troubleshooting does not restore cooling to your home or you need professional air conditioning repairs, call us today and schedule an appointment.