Why Is Your Ceiling Fan Not Working On All Speeds

Ceiling fans are a great alternative to air conditioners and serve a major role in cooling down rooms throughout the summer. Like all major electrical fixtures, fans require maintenance. Without the necessary maintenance, ceiling fans may begin to have issues with functioning, some of which are easier to solve than others.

The reason for a ceiling fan not working at all speeds could be due to a number of factors. This could be due to issues with bearings, blade balancing, faulty capacitors, and damaged winding. Other possible causes of this issue could also be old blades, a damaged pull cord, or even loose screws.

There are numerous ways in which one can troubleshoot a problematic ceiling fan. This will assist you in determining the cause of the issue. Through a simple process of elimination, it will be possible to identify the main cause of the problem, hopefully without the need for an electrician’s intervention.

Image of a ceiling fan with 5 blades
A ceiling fan with 5 blades

Troubleshooting Your Faulty Ceiling Fan

Ceiling fans that spin at a slower speed than usual are likely to have one of four issues. The loss of bearing lubrication and poor blade balance are two mechanical concerns. The other two are electrical in nature: a faulty capacitor or a faulty winding. 

Other issues include old fan blades, loose screws, a damaged pull cord, or even a motor that is overheating.

Ceiling fans have low torque, therefore practically any issue can cause the fan to run slowly.

In order to begin troubleshooting potential issues, spin the fan blade with your hand while the fan is turned off and stopped. 

A difficult-to-turn blade suggests a bearing or lubrication issue. If this is not the issue and the blade spins freely, turn on the fan and listen as the blade accelerates to full speed. 

Any strange buzzing while the fan accelerates towards full speed could suggest a faulty capacitor, a shorted winding, or the use of the incorrect speed control device for the fan.

The control box itself could simply be faulty, and replacing this could be another potential fix for the fan.

Because most fans and solid-state speed controllers are incompatible, double-check that your fan and speed control are compatible. 

In addition, a grinding or screeching noise indicates a problem with a bearing or bushing. 

Finally, it would be advisable to visually inspect the fan for any wobbling that could indicate improper balancing.

If the fan is stuck at a low speed, it is highly probable that a faulty capacitor is the issue. A capacitor determines how much power moves to the fan motor. 

If this capacitor is faulty, only a small amount of electricity will go to the motor, causing the fan to remain at a low speed instead of accelerating towards the desired speed.

If the fan remains at a high speed and refuses to change speed, it is most likely that there are no issues with the capacitor, but perhaps problems with the pull cord.

Identifying A Faulty Capacitor

Ceiling fans use capacitors to start and run because they are single phase motors. Some fans contain a capacitor that serves as both a start and a stop, while others have separate capacitors for each.

For speed changes, some fans employ numerous capacitors. Turn the breaker that powers your fan to the “off” position in your breaker box. Remove the lower cap on the fan that generally houses the capacitors.

While the disassembly method varies depending on the fan, the capacitors are easy to spot. The microfarad rating will be printed on the side of little black cubes or silver cylinders. 

A number will be followed by the letters “uf” to represent the capacitor rating. Examine the cube or cylinder for any distortion that could indicate a capacitor failure, and replace any that are swollen or discolored.

Wire nuts link the capacitors to other wires, or they are attached to screw terminals. Disconnect the faulty capacitor and order a replacement based on the information on the label.

What Is a Capacitor And How Does It Work?

Upon inspecting the workings of a ceiling fan, you will find a black box in the switch housing. This black box is referred to as the capacitor, and it is an essential part that allows the fan to work properly.

It allows the fan not only to start, but also to spin and continue spinning. Magnetic flux (also referred to as torque) is created by the capacitor, thus allowing the fan to rotate.

How To Replace a Capacitor

In order to replace a faulty capacitor, one must first remove the fixture from the fan and disconnect the wires, gaining access to the fan’s motor.

Once the motor is visible, it is easier to locate the capacitor which is usually located near the pull switch (if applicable to this type of fan).

Cut the wires of the capacitor as close to the capacitor as possible (there may be anything between 2 and 5 wires). Remember to make a note of which wires are attached to one another, as this will naturally impact the installation.

In order to replace the capacitor, you will need to find a replacement capacitor identical to the one which is being removed.

The easiest way to ensure that you are obtaining an identical replacement is to take the old capacitor to the store at which you are planning to make your purchase.

Once you have your new capacitor, attach it to the fan housing using a screw, and use wire strippers to expose around ¾ inch of bare wire on each wire in order to perform the splice. 

Twist the correct wires together and attach a wire cap onto each connection.

Once this is complete, you are ready to re-mount your fixture and test the fan to see if it is working correctly.

Conclusion

As can be seen from the above, a ceiling fan that is not working at all speeds could be performing in this way due to numerous factors. It is important to troubleshoot correctly in order to ensure that you are able to fix the problem with the least cost involved, in terms of time and money.

Charles John

A novice DIYer who learns about home ventilation. I am a mechanical engineer and have a basic knowledge of HVAC systems but I learn continuously to make myself the best blogger in that space.

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