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Why is The AC Blowing Warm Air?

Why is The AC Blowing Warm Air?

Air Conditioning Repair | AC Blowing Warm Air

With the days now warming up, some homeowners have already turned their air conditioning on. Without a doubt, some have encountered the problem of the AC blowing warm air, and have required air conditioning repair.

While there are a number of potential causes for the AC blowing warm air, some are a simple fix for homeowner’s that require no tools or knowledge of HVAC. We will cover the most common causes, and how you can get the air conditioning back on your own.

Thermostat Setting

It happens often, so don’t feel bad if it happens to you. Check your thermostat setting and ensure it isn’t on “heat”. It is easy for it to occur during the spring and fall when a little heat is needed at night, and air conditioning is required during the day. A programmable thermostat can automatically take care of this issue for you.

Check the fan setting. If the fan setting is “on”, rather than “auto” the fan will run continuously. When the outside condenser isn’t running, the air exiting the vents will be warmer. Someone may have bumped the fan to run with a window open to air the house out, resulting in the AC blowing warm air when the compressor isn’t running.

Dirty Air Filter and/or Coils

A dirty air filter or coils can cause the outdoor compressor to freeze up due to insufficient air flow, resulting in the AC blowing warm air. Depending upon the type of filter, you may need to change it monthly. Pleated filters are typically changed every three months, and some filters are engineered to be cleaned. Check the filter at least each month if not more often, and change/clean it when soiled.

Dirty coils will require contacting your HVAC technician for maintenance. When your system is serviced annually or ideally bi-annually, this problem shouldn’t normally occur. When the coils are cleaned annually and your AC is blowing warm air in the absence of a dirty filter, move on to the next check.

No Power to the Condenser

The air conditioning system consists of an outdoor condenser and an indoor blower unit. The indoor blower unit houses the fan that forces the cold and dehumidified air through your home’s duct system, as long as the outdoor condenser is working.

Check the circuit breaker in the home’s electrical service panel to ensure it hasn’t tripped. If you have an older electrical panel, the fuse that protects the electrical circuit for the air conditioner may be blown. A circuit breaker can simply be pushed back into the “on” position. If it trips again, there is a problem with the electrical circuit or the condenser, contact your HVAC technician for diagnoses and repair. Replace a blown fuse, and if it blows again follow the same procedure.

A power surge can cause the safety circuits to blow, or shut off. However, repeatedly tripped breakers or blown fuses indicate a potentially serious issue. Depending upon the system design, there may be an additional breaker located indoors or out. Outdoors it will typically be located in a service box near the condenser. Check the wall, or under a deck if located near the condenser. Indoors, split systems may have a fan switch and dual breakers inside the unit’s air handler indoors. A tripped breaker can cause the system to not have power, while a tripped fan switch will cause the fan to not operate.

As previously stated if this is more than an occasion occurrence with power surges, have your HVAC system inspected and serviced by a qualified technician.

Outdoor Condenser

Check the outdoor condensing unit. Have you removed the winter cover before using the air conditioning for the first time this season?

Is anything blocking the condenser coils and air flow? Blockage will impact the condenser’s performance, and may result in damage to the unit.

The condenser coils may be in need of a professional cleaning, just like the coils inside, dirt will impact the system performance.

Refrigerant Leak

A refrigerant leak is a common cause of the AC blowing warm air. If the system is low on refrigerant the ice will form on inside and outside components, dependent upon the type system that you have. Contact your HVAC technician for repair and charging with refrigerant.

Cypress Heating and Air Conditioning provides professional heating and air conditioning service. When the AC is blowing warm air contact our certified HVAC professionals for air conditioning repair or installation. You can rely upon us for your comfort. We serve Katy, Plano and the surrounding areas, and are a member of the BBB with an A+ rating.