In many cases, using a window fan in your home can help move air and make your home more comfortable without the expense of an air conditioner. However, if your window fan ceases to function correctly, you can either purchase a new one or attempt to repair it yourself. Most problems with window fans are relatively simple to repair and can be done if you possess basic knowledge of electricity, electrical circuits, and are handy with a few basic tools.
1. Check the Cord or Power Switch
Before doing anything else, you should check the cord or switch of your window fan for continuity. Over time, electrical cords can become damaged or creased in a way that prohibits electricity from being properly conducted. To check the continuity of your electrical cord or in-line power switch, use a multi-meter meter set on RX1 (resistance times 1). You will need to disconnect the power cord from your window fan in order to do this. If a faulty cord or in-line power switch is the culprit, simply replace it.
2. Check for Blown Fuses or Damaged Wiring
Many of today's window fans use fuse protection to protect the window fan motor from overheating or damage. Check the wiring housing area of your window fan to see if there is a fuse that is blown and needs to be replaced. Some fans use an in-line fuse rather than a common bulb type. Check for burnt or broken wires that may be keeping your fan motor from receiving power. Replace fuses or reconnect broken or damaged wires as may be needed.
3. Oil the Motor Shaft
Another common problem with all types of fans, not only window fans, is a lack of lubricant on the shaft of the motor. Remove the blades from the shaft and lubricate the shaft with a high-quality lubricant. Using graphite or a silicone-based lubricant will usually be the best as they provide for the smoothest rotation of the shaft and last the longest.
4. Stop Humming in Your Window Fan
If your window fan is making unusually loud humming noises, it is probably because the bushings in the window fan are dry or damaged. To determine if the bushings are bad, take the fan apart and thoroughly clean the front and back bushings and oil them slightly. If the humming sound continues, you will need to change the bushings for your window fan.
5. Replace the Motor
If you've tried everything else, and your window fan still does not work, then the motor of your fan is probably defective and will need to be replaced. Remove the motor unit from the fan and take it with you to your local home improvement store. If your local home improvement store does not carry a replacement motor, visit an electrical supply store and ask for a suitable replacement. Alternatively, you may want to call the manufacturer and see if they have a replacement motor available for your unit.