There’s nothing more annoying than a faulty AC system blowing hot air on a warm day. When it comes to broken ACs, it’s difficult to pinpoint the exact cause – there are many, which makes it frustrating.
10 Common Causes of AC Not Blowing Cold Air
If your AC emits warm air, you must schedule an emergency AC repair with a professional technician. Still, it’s good to know the possible reasons, in case it’s just a blocked vent or an incorrect setting.
- Incorrect Thermostat Setting Your AC temperature settings may be incorrect. Make sure your AC is set to “cool” and not “warm” or “fan.” Ideally, air conditioners should be set to around 71 – 78 °F to ensure your space is comfortable and you save on energy bills.
- Low Refrigerant Coolants or refrigerants are the magic substances that run through your AC’s interior to cool the passing air or condense water into humid air. It’s how ACs produce cool air. If there’s too little coolant, your AC won’t be able to absorb heat through its coils. It’ll just blow out warm air. Although it’s likely normal wear and tear, you must hire a technician.
- Broken Compressor The compressor circulates coolant through your AC system. If faulty or broken, your system won’t compress the refrigerant; thrust can’t absorb the heat inside the house to release it outside. This serious problem requires a professional technician’s help.
- Clogged Filters You may need to check or change your AC’s filters. Dust and dirt restrict airflow from passing through, causing your AC system to work harder and limiting its cooling capacity. Not only does this produce warmer air, but it snowballs into higher energy bills and potential overheating, leading to costly repairs.
- Damaged Capacitor An AC capacitor stores and releases electrical energy needed to make your system run smoothly. A faulty capacitor can affect an AC compressor or motor fan, significantly reducing cooling capacity.
- Frozen Coils AC evaporator coils absorb hot air inside your home and transfer it outside. If they get too cold, they can freeze, blocking airflow and producing warmer air. Dirty air filters, low fan speed, or backup drain clogs are common causes
- Leaky Ducts The air vents in your house should always be cold. However, leaks can pull cool air out and warm air into your AC system. This may be wear and tear or something more serious like a pest infestation, high humidity, or installation errors.
- Faulty Circuit Breaker A faulty circuit breaker can cut off the power supply to your AC unit. As a safety feature, it’s supposed to protect the AC system, but if the wiring is bad or a power surge causes a short, it might trip the system.
- Blocked Return Vents Return vents pull warm air from inside toward your AC unit, where it’s cooled. When blocked, they can’t pull enough warm air from inside the house, leading to warmer air exiting the vents. The solution? Just remove whatever is blocking them and make sure they’re open.
- Outside Unit Power Loss If your AC’s outside unit loses power, it stops cooling air. However, your interior system may still blow air around, even though it’ll be warm. It’s easy to miss this issue, especially when the power loss is confined to your outdoor unit.
Should I repair my AC myself or call a professional technician?
While there’s nothing wrong with changing the filter and removing debris around your AC system, licensed professionals should handle any other maintenance or repair tasks. HVAC technicians are specially trained to ensure your unit runs optimally throughout the year by performing the following tasks:
- Cleaning the coils
- Inspecting and unclogging the drain
- Checking and testing refrigerant
- Examining airflow
- Testing electric controls and terminals
Attempting to DIY these tasks could injure yourself or damage your AC system.
Rely on 1st Call Plumbing for All Your AC Troubleshooting
Whether you need an AC tune up or AC emergency repair, 1st Call is always ready to
help. Our technicians have fixed hundreds of ACs blowing hot air. We’ll get yours back to normal so you can stay cool in warm weather. Contact us now!
