Aircon Unit Fan Motor

The aircon fan motor drives the aircon fan, which blows air in and out of the house. This is important for moving hot air to the outside of the building, as well as blowing cool air through the ductwork and into the rooms. The fan motor is a vital part that must be running well for the aircon unit to do its job.

Because the fan motor is one of the hardest working parts on an aircon unit, it is subjected to a lot of wear and tear that can lead to frequent repairs or replacement. And the cost can add up when you start thinking about costs to replace including labor cost. Once the fan motor breaks down, the aircon unit will stop blowing cold air and that’s something you don’t want on a hot summer’s day.

What causes aircon fan motor failure?

The main causes of an aircon fan motor failure are:

1) Loss of lubricant 

2) Failed run capacitor

3) Failed bearing in a belt drive

4) Water dripping into the windings or a voltage problem. 

These are important to not note so your trusted professional aircon servicing company should carefully check to find the cause of a failure before changing the motor:

How to prolong the life of your aircon fan motor?

One common reason an aircon fan motor burns out is due to dirt building up around the fan motor. Dirt can creep into the holes of the motor, causing more friction for the inner workings which stresses the motor and causes overheating. The fan motor is one of the hardest working components in your aircon unit and wear and tear will eventually take its toll. However, you can prevent it from burning out sooner than intended with regular aircon unit maintenance

1) Regular dusting in and around the motor hole can prevent this. This easy maintenance task helps prolong the lifespan of the fan motor and can prevent more serious aircon issues.

2) Ensure regular maintenance is to sign up for a maintenance plan with your professional aircon servicing company. They will check on things like compressors, fan motors, and furnace motors for you. Most maintenance plans include biannual aircon unit tune-ups.

As part of a routine maintenance visit, the professional aircon servicing company will inspect the condenser unit, clear away any dirt or leaves that have accumulated on or around the aircon unit, check the fan, and, if necessary, clean the fan motor and oil the bearings.

Steps to identify if there’s a problem with your aircon fan motor:

If your aircon fan motor seems bad or the capacitor is faulty, you should always contact a professional aircon servicing company to repair or replace parts. However, there are some preliminary steps you can take to rule out other possible causes if your aircon unit is not working and confirm that the problem is, indeed, with the aircon fan motor.

1) Check the circuit breaker

Sometimes the reason for an aircon unit that’s not working is as simple as a tripped breaker. The first step is to check the circuit breaker. When the aircon unit goes on the blink, a tripped circuit breaker isn’t the first thing that comes to mind for most people, yet it is a surprisingly common reason for an aircon unit to not start.

2) Check on the filters

Many homeowners neglect this basic maintenance task. A clogged air filter reduces airflow. If the air filter is clogged, replacing it with a new one should get the air flowing freely and strongly again.

3) Check the outdoor unit

If you’ve ruled out the above problems, it’s time to head outside to the condensing unit. If your aircon unit has stopped blowing air, has weak airflow, or you hear unusual noises, do a quick inspection of the fan motor. The motor is located in the condenser unit. Listen for a humming sound that tells you the aircon compressor is functioning.

Pro 338 Tip: You may also try to check through the vents at the top of the aircon unit to see the fan. Are the fan blades turning? If the compressor is working but the fan blades are not spinning, the motor is faulty. That’s your cue to turn the aircon unit off and call the professional aircon servicing company to repair the aircon fan motor.

5 signs of a failing aircon fan motor:

When your aircon unit suddenly breaks down, it’s difficult to know where to start in identifying the problem. Here are five signs that tell you that you’re dealing with a failing aircon fan motor:

1) The fan won’t start even though your aircon unit is on

When the fan does not start even though the aircon unit is turned on, it can be a clear sign that there’s a fault with the motor. When the aircon unit runs without the fan circulating air, it can eventually lead to the evaporator coils freezing over. Once this happens, your aircon unit is at risk of suffering more serious damage. Turn off your aircon unit and call a professional aircon servicing company for this aircon issue.

2) The fan continues to run, even when shutting off the aircon unit

The opposite problem can also occur as well, the fan continues to run even after switching off the aircon unit. This can be a sign of a bad blower motor resistor. In some cases, this is caused by a malfunctioning thermostat. Replacing the thermostat will have it up and running again.

If the thermostat isn’t the main aircon issue, the most likely problem is a stuck relay switch. Relays are what open and close the electrical circuit in an aircon unit. When a relay becomes stuck, the circuit remains closed. As a result, electric power to the fan motor doesn’t stop and the fan continues to run.

3. The fan is on but rotating very slowly

Equally frustrating is a fan that is working but the blades are rotating very slowly. A slow-turning fan will generate weak airflow. If your aircon unit offers different fan settings, check if it is set at low speed. If that isn’t the case, it could mean the motor bearings need to be oiled or that the capacitor is failing.

4. The fan runs intermittently

When the fan runs intermittently, it could be one of two problems. The motor could be overheating which causes it to cut out. Alternatively, a loose wire or connection or a short in the motor windings could be the culprit.

Any electrical-related faults should only be addressed by a professional aircon servicing company. Never attempt to work on a fan motor when you suspect an electrical issue. This can be dangerous and is a job best left to a professional aircon servicing company or electrician.

5. There’s a rattling or buzzing noise coming from the aircon unit

There is more than one possible cause for a noisy aircon unit. If you hear a loud rattling noise, it could be a minor aircon issue like loose stones or debris that’s caught in the condensing unit. A rattling noise can also be caused by loose or unbalanced fan blades striking the side of the fan housing unit.

Pro 338 Reminder: If you don’t see anything stuck in the condensing unit and the fan blades are turning freely and smoothly, then the likely cause is the fan motor. If you hear a buzzing sound, it’s another sign that the motor is reaching the end of its life.

Repairing or replacing your aircon fan motor: 

Replacing an aircon unit motor is a job that can be done quickly once the problem is identified. With the information you have provided, the professional aircon servicing company will take the following steps to confirm the problem and ensure your aircon unit will be back to its optimum performance:

1) Conduct a visual inspection

A professional aircon servicing company can quickly spot certain problems on a visual inspection of the condenser unit. For instance, after long hot summer days, moisture or rust can build up in the fan unit preventing the blades from turning.

2) Check the condenser unit’s temperature

Condenser fan motors all have a temperature stipulated by the aircon unit manufacturer at which they can operate safely and problem-free. In most cases, the ideal temperature is around 150 degrees Fahrenheit. If you are near the condenser unit and it feels hotter than usual, it indicates that the fan motor may be overheating. Professional aircon servicing companies are equipped with an infrared temperature gun that can read the unit’s temperature without having to touch the hot surface.

3) Check the capacitor

The start capacitor is a cylindrical component that supplies the electric charge that starts the condenser fan motor. It plays a vital role in starting up your aircon unit. Without that boost of power, the fan motor is unable to start. That’s why when the capacitor stops working, so too does the aircon unit.

Pro 338 Reminder: Don’t try to remove or fix the capacitor yourself. If the aircon unit is still switched on, the electricity that runs through the capacitor can result in a serious electric shock, injury, or even death. Capacitor problems should only be attended to by a professional aircon servicing company or electrician.

4) Inspect the electrical wiring

If none of these is the aircon issue, the professional aircon servicing company will check the condition of the electrical wiring and the windings to see if it is open or has a short. If switching on the aircon unit frequently causes the circuit breaker to trip, it’s likely due to a short in the windings.

The professional aircon servicing company will do a resistance check by measuring the ohms. If the resistance is zero, it means there’s a short. If there is an infinite reading, it means there’s an open winding. In both cases, the motor will need replacing.


It’s always a good time to talk about the common issues that aircon units have. This way, you’ll be able to spot if there are problems with your unit or not and prepare for its replacement accordingly. If you require our aircon servicing services, Whatsapp us at +65 9222 4141 for a fast and transparent quote.

338 Aircon Servicing Singapore provides an extensive range of Aircon Services including Aircon Servicing, Aircon Repairs, Aircon Installation of best aircon brands, Chemical Overhaul, Gas Top-up, Aircon Leaking Water, and Aircon Not Cold Fix and more. We have a team of professional technicians who are equipped with vast knowledge and experience in the Aircon industry. 

We have over 15 years of experience in dealing with aircon works and have completed thousands of aircon works for both residential (Landed, Condo, and HDB) and commercial. We are a highly recommended Aircon Company in Singapore, with many delighted customers and reviews over the years on Google and Facebook. WhatsApp us at +65 9222 4141 for a transparent quotation and honest pricing for all your aircon needs or Call us at +65 9222 4141 . We offer a fast and efficient service to serve any of your aircon needs!