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  • Reasons Why Your AC Fan May Not Be Working


  • April 25, 2022

    Summers can be sweltering in some parts of the United States, and conditions can quickly become intolerable if your AC system breaks down. In some cases, the heat and humidity can be so extreme as to endanger the health of susceptible people, particularly senior adults and children. 

    Unfortunately, air conditioners can stop working suddenly, leaving you at the mercy of unforgiving temperature extremes. And more often than not, the malfunctioning component is the fan. 

    What does the AC fan do?

    Most modern AC systems intended for home use have a condenser unit. In split-type systems, this is the big box installed outside. The condenser has an array of cooling coils that convert refrigerant gas into cool liquid when the fan blows over them. This process is what allows air conditioning systems to cool your home. 

    This system relies on the fan to work continually. When it malfunctions and stops for whatever reason, the refrigerant will not be cooled and the air conditioner will not be able to cool the room. 

    Why do AC fans stop working?

    There are many reasons why AC fans stop working. Unfortunately, most of them aren’t easy fixes, which means you will probably have to call an HVAC technician to diagnose your unit and fix the faulty component. Here are some of the most common reasons why AC fans stop working: 

    1. Bad capacitor

    One of the most common reasons for fan malfunction is a bad capacitor. These components provide electrical energy to the air conditioner’s motor, starting it up initially and then keeping it running. 

    You can tell a capacitor has gone bad when you notice the following: 

    • Slow or sluggish starts 
    • Unexpected shutdowns 
    • Inability to blow cold air
    • Loud humming sound

    2. Faulty motor

    The condenser’s fan is driven by a motor that provides the electrical charge necessary to turn the blades. When the motor fails, the fan won’t work and won’t be able to cool the refrigerant liquid in the cooling coils. 

    Most motors are designed for years of operation, but they will fail at some point. When this happens, it may require repair or replacement depending on what components failed and the extent of the damage. In any case, it will be necessary to have it checked by a technician to get it back in working order. 

    3. Contactor issues 

    AC units have contactor devices that control the flow of electricity throughout the system. As you set the temperature on the unit’s thermostat, the contactors conduct and restrict electricity as needed to get your air conditioner to start or stop. 

    But like many components, contactors can burn out over time. Whether this occurs due to wear and tear or overheating, they will have to be repaired by an HVAC technician. 

    4. Broken fan belt

    Another component that is prone to breakage is the fan belt. If your AC is relatively new, it probably doesn’t utilize a belt drive system, relying on direct motors instead. But if you have an older unit, a broken fan belt might be the reason why your fan failed. 

    Why do fan belts break? Like motors, fan belts are usually designed for years of operation. But they do become weak and brittle over time. The longer you use your AC, the more likely the belts are to fray, tear, or snap. When this happens, you will have to get a replacement fan belt. 

    How can you tell if your fan belt is broken? If you can’t get a visual of it, you might hear unusual sounds coming from your unit. Clicks, clangs, and squealing or squeaking sounds usually indicate a problem with the fan belt. 

    5. Broken blades

    Finally, broken blades may be the reason why your AC fan isn’t working. This doesn’t happen very often but it may occur for various reasons, including age, neglect, or a foreign object entering the air conditioner housing. 

    In any case, you should be able to see the fan through the vents of your AC or outdoor unit. If it is missing a blade or one or more of them seem bent or cracked, that is probably the reason for the fan’s failure. 

    If one or more blades have broken off, it will be necessary to replace the entire fan. Have an HVAC professional inspect your unit and determine the appropriate replacement for the fan. 


    Don’t wait until your fan breaks down to have your air conditioner checked! Periodic inspection and maintenance might seem like a bother, but it can save you from a more expensive repair or replacement costs later on. 

    Furthermore, having your AC system checked will help identify potential problems before they occur, so you won’t have to be without an air conditioner when you need it during the hot summer months. 

    J.A. Bertsch

    J.A. Bertsch Heating & Cooling offers professional residential air conditioning services throughout Kootenai County. Our licensed A/C technicians cover all of North Idaho and our neighboring cities. Experience superior, award-winning service 24/7. Call us at 208-635-5480 to schedule an appointment.