When your air conditioner 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 AC fan motor.
1. The Fan Won’t Start Even Though The AC Is On
When the fan doesn’t start even though the AC is turned on, it can be a clear sign that there’s a fault with the motor. When the AC runs without the fan circulating air, it can eventually lead to the evaporator coils freezing over. Once this happens, your air conditioning unit is at risk of suffering more serious damage. Turn the AC off and call an HVAC technician.
2. The Fan Continues To Run, Even When Shutting Off The AC
The opposite problem can also occur, i.e. the fan continues to run even after switching off the air conditioner. 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 issue, the most likely problem is a stuck relay switch. Relays are what open and close the electrical circuit in an air conditioner. 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 AC 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. 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 trained HVAC technician or electrician.
5. There’s A Rattling Or Buzzing Noise Coming From The Condenser Unit When The Fan Is Turned On
There is more than one possible cause for a noisy air conditioner. If you hear a loud rattling noise, it could be a minor 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.
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.
Contact Person: Ms. Amanda Gu