How to Tell If Ceiling Fan Capacitor Is Bad | Expert Guide

Because ceiling fans are energy efficient, they are the preferred choice for homeowners who have central air conditioning and use them all year round. The capacitor is an important component of a ceiling fan motor. When the fan is running, it stores energy to continue to run even when the blades are not moving. Let’s learn how to tell if ceiling fan capacitor is bad.

Ceiling fan motors are powered by capacitors, which can malfunction. Ceiling fan motors are powered by capacitors, which are susceptible to failure. This article explains how to tell if a ceiling fan capacitor is bad and how to replace a damaged fan capacitor.

What is a Ceiling Fan Capacitor?

How to Tell If Ceiling Fan Capacitor Is Bad

A capacitor is a device that stores electricity and releases it during periods of high demand. Ceiling fan condensers are among the most important components that can be damaged in a ceiling fan. It is an energy storage device that looks like a battery, but the charge is stored by an electric field, not by chemicals used to store energy.

Can a ceiling fan work without a capacitor?

How to Tell If Ceiling Fan Capacitor Is Bad

A ceiling fan is a rotating electrical machine that can move air or rotate another object. The ceiling fan condenser is the energy source needed for the ceiling fans to function properly. If there were capacitors there, it would be not easy to start the ceiling fan, and it might not move at all.

Why is the Ceiling Fan Attached to the Capacitor?

Why is the Ceiling Fan Attached to the Capacitor

There are two types of windings available in the ceiling fan motor. The first is the start winding, and the second is the stroke winding. Ceiling fans are generally single-phase units. The starting torque is required to start the fan. This is impossible without a capacitor.

Therefore, a phase shift is required between the two windings to start the torque. Therefore, the capacitor and the starting winding are connected in series.

How to Tell If a Ceiling Fan Capacitor Is Bad

How to Tell If a Ceiling Fan Capacitor Is Bad

If the ceiling fan’s capacitor is defective, the fan receives the same power as usual. But since the capacitor is bad, its starting winding will not receive enough power, so the starting torque will not be generated. Since there is no phase difference between the two windings, the motor will try to run, but it will not be able to run due to the zero-starting torque. You will hear a buzzing noise due to this problem.

The following are the signs when a ceiling fan capacitor is bad.


  • If you notice melting or fire around the capacitor due to overheating, this is in most cases confirmation of a defective capacitor.

The fan is not spinning.

If the fan does not start rotating after turning on the switch but rotates by pressing the blades with your hand, the capacitor is not in good condition.

Slow fan rotation

If the fan speed has been reduced, one of the reasons may be a defective capacitor. This can be verified by checking the capacitor with a millimeter.

The fan does not work at certain speeds.

Few fans have speed controllers. If the fan spins slowly or stops at a certain speed, you will need to replace the capacitor.

Poor multimeter reading

If you doubt a capacitor, you can test it with a multimeter. If the multimeter shows unpleasant readings, the capacitor is defective.

Identifying and repairing a faulty ceiling fan capacitor

Check the voltage across the capacitor. If the voltage is within specification and not a problem, the capacitor is likely defective.

  • Locate and remove the ceiling fan capacitor (fuse box or breaker). It is best to leave the ceiling fan on when replacing the condenser to ensure that it works.
  • Check the new capacitor with an electronic voltmeter.
  • Connect the wires, and then turn on the fan to test the capacitor. If it is defective, you will need to replace it with an equivalent of the same size or larger.

How to Replace the Ceiling Fan Capacitor

How to Replace the Ceiling Fan Capacitor
  • Locate the part to be replaced and begin replacing the old part with a new one.
  • Turn off the power to the fuse board or remove the circuit breaker and check the voltage before touching the wire (usually not after disconnecting the power).
  • Remove the old capacitor, pay attention to the polarity, and then notice how the old capacitor was connected.
  • Install the new capacitor in place and connect it according to the wires of the previous one.
  • Apply power to the fuse board, and then reconnect. Check the ceiling fan to ensure the condenser is in good working order. 

Frequently Asked Questions

What can cause the ceiling fan’s capacitor to fail?

If the capacitor is defective, the fan is still energized, but it cannot generate enough torque to start the fan since the starter coil is damaged. You may, however, manually start the fan by pressing it, and it will continue to run. If the capacitor fails, the fan may also run irregularly.

How do you check the capacitor on a ceiling fan?

Count to three while the meter wires charge the capacitor. Swap capacitor leads. Note the movement of the meter needle towards infinite resistance. The capacitor is faulty if the meter does not get to infinite resistance.

What happens if you don’t use a capacitor when running a fan?

Without a condenser, you can manually revolve the blades of a ceiling fan. The ceiling fan begins to rotate in which the blades are manually rotated. Because this is a time-consuming manual process, it is automated using a condenser attached to the ceiling fan.

Why do I have two capacitors in my ceiling fan?

In the ceiling fan, two capacitors are used in series. The fan motor is known as a “Dual Rating Capacitor Motor.” A phase-separated motor’s starting and operating windings have high and low capacity.

How can you tell if a capacitor is in good working order?

The capacitor has a positive voltage anode and a negative voltage cathode. To test if a capacitor is operating, charge it with electricity and measure the voltage across the anode and cathode.

What causes the failure of the fan capacitors?

The condenser might be lit if the compressor or fan motor fails due to faulty or worn bearings. Lightning can damage the condenser, air conditioner compressor, fan motor, and appliance cables. A small amount of overvoltage might damage or destroy the capacitor, causing the compressor to overload and fail.

Can a defective capacitor damage the motor?

The use of low-quality condensers can hurt the engine, compressor, and the entire HVAC system. Depending on the load on the motor, this can lead to a decrease in the overall speed of the motor. 


Being able to detect a defective capacitor is critical to be repaired before it causes further damage to what has already been damaged.

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