Help! Why Is My AC Fan Not Spinning?

In short, common issues that can cause an air conditioning unit fan to stop spinning are electrical issues, problems with the capacitor, contactor issues, a burnt out air conditioner motor, a broken fan belt, or clogged air filter.

There is nothing worse than having an air conditioning unit malfunction just as summer weather really starts to kick in. A common issue is that the unit appears to be working, yet the fan is not spinning, and the air from the system isn't getting cool. This can be highly frustrating, leaving your family to sweat it out inside without any cool air.

Depending on a reliable air conditioner this summer is vital to everyone's home comfort. There are several reasons may be causing your air conditioner fan not spinning. Let's look at why this may be and what you can do about it.

Diagnosing Your AC Fan Problem

To discover the cause of your AC fan not spinning, it is essential to have a basic understanding of how the HVAC functions. The air conditioning system essentially blows cold air from the outdoor unit into your home. Your home's walls help keep the cool air inside, so having good insulation is important to your system.

There are two AC fan motors that are essential to your AC system. The inside of the home has one, and the outdoor AC fan is the other. The indoor blower fan directs cool air into the house. The outdoor fan helps remove the hot air from your home. If you experience either AC fan not working, it affects the efficacy of your HVAC unit leading to lukewarm air blowing into your home.

To ascertain if you are suffering from a bad fan motor, you can listen to the unit from the outside. Listen for a humming noise — this means the fan blades are working. If you hear a hum but notice the AC unit fan not spinning, then there could be one or more things wrong with the unit.

How Air Conditioner Fans Work

The HVAC fans are made to spin by the capacitors and motors within the unit. It works similarly to a car's motor. The capacitors are like batteries — they store the energy that makes the unit work. There is a run and a start capacitor. The capacitors are linked to the fans, so the fans should work when energy flows through them. Without the motion of the fans, the air will not be moved properly, and thus the until will not cool your home.

The best way to keep your AC fan motor running properly is to ensure it gets regular maintenance and air conditioning repairs by a professional.

Common Reasons Your AC Unit Fan is Not Spinning

If you notice the problem of your AC fan not spinning, this is a clear indication that something is wrong with your unit. You will need to get an HVAC technician to come and professionally diagnose and repair the issue. In the meantime, it may help if you understand what is going on to explain the problem to your technician when they arrive.

Let's explore each potential issue individually.

1. Power Issues

The reason for your AC unit fan not spinning could simply be a power issue. If the system is overheating, your breaker may trip. Subsequently, your AC fan will stop spinning, and the unit won't work. If the matter is not serious, you can just go to your circuit breaker box flip the switch back on. If the circuit breaker continues to trip, you may need an electrician or an HVAC specialist to come and sort the matter out.

Treat your breaker box with care. It contains high voltage and touching the wrong wire could lead to an electrical jolt. If you don't feel comfortable around your circuit breaker, it's best to call an electrical or HVAC technician that is trained.

2. Capacitor Problems

One of the top reasons your AC fan may not be spinning is if the capacitor is dead. A fan's capacitor is a small, cylindrical component that transmits energy signals that power the motor of the fan and the overall AC unit. An AC unit typically has several capacitors in it — all the various capacitors are created to perform individual tasks. These include:

• The Start Capacitor. This component sends energy signals directly to the motor.
• The Run Capacitor. This part keeps the motor going.

Capacitors fail over time and require replacement. If a failed capacitor the source of your problems, it will need to be replaced in order for your HVAC system to run properly again.

3. Contactor Issues

If you notice the AC fan not working, it could also be caused by a problem with the compressor contactor. The unit's compressor switch sends electricity voltage to the fan and condenser unit. This gives them the power they need to run. 

The switch is located in the compressor unit. These switches typically wear out and break down over time, which causes the fan to stop spinning and the unit to stop working. If this happens, the contactor will need to be repaired or replaced.

4. The AC Fan Motor Burnt Out

If you see the AC fan not spinning, the fan motor may have burnt out. If the fan motor has been working very hard and hasn't received regular annual or biannual maintenance, motor bearings can break down. Fan motors can be quite pricey to fix or replace. You may end up having to replace the entire system.

Ensure your unit gets regularly seen by a technician to avoid this issue.

5. Broken Belt

Old AC condenser models run with a belt. When these get older, they can break or slip off. This is not a complex problem to fix, and your HVAC technician will be able to sort it out for you quickly and affordably. However, if the belt is giving you trouble regularly, it could be time to replace the AC unit.

6. Clogged Air Filter

If you see the AC fan not working, it could also be because of a clogged air filter. Clogged filters stop the air from flowing freely, leading to a build-up of ice in the unit. This puts a lot of strain on the AC unit fan, which can cause a breakdown. To maintain a well-working fan and keep the system functioning correctly overall, service and change air filters routinely.

Keeping Your Home Cool

It may be tempting to try to service the AC yourself. However, being tempted to save yourself a buck can cost you more serious damage to your cooling system and run the risk of complete system replacement.

If your AC fan is not working, the best solution is to call the certified HVAC technicians at ARS/Rescue Rooter. Once our Comfort Specialists have your fan spinning, you can enjoy a comfortable home all summer long.

Call us now at 866-399-2885 or find your nearest ARS/Rescue Rooter location to schedule air conditioning service today!