How to Replace a Whole House Fan Motor

Whole house fan systems are a popular way of keeping an entire house cool, simply by using a large fan. These fans are typically attached to the sides of attic roofs or louvers, and may be an energy loss during the winter, but in summer they provide a lot of cooling energy for their efforts. As well as being used to cool, a whole house fan can be used to clear air and odors out of the house quickly, so that pollutants and allergens can easily be moved from the house. However, the worst part of using a whole house fan is replacing the motor inside. By following a few simple steps, you should be able to get the motor replacement done quickly and easily, and relax in the cooling breeze of your fan.

Step 1 - Removing the Cover

If you have any problems reaching the fan from a standing position, try using a step ladder, but don't go too high. If you still cannot reach while using a step ladder, consider calling in a professional, and letting them take the risk.

Once you have reached the whole house fan, locate the screws which hold the cover on to the main body. There should be screws along each edge, so make sure that you find and unscrew each nut before you proceed. Once all of the screws are loose, take down the cover, and either place on the floor, or hand to a nearby assistant.

Step 2 - Removing the Old Motor

Locate the motor. You should be able to hold onto the motor while removing the wires and connections that hold it in place. Unlike a smaller fan, there are no belts to remove, so just locate the connections, and take these away (you may need to unscrew the wires in order to remove them). Unscrew the motor from its frame, and then take the motor off of the fan and discard.

Step 3 - Replace the New Motor

The new motor can now be put in the old motors' place. Carefully insert the motor into the frame, taking care to position it so that the power wires can easily be attached. Fit the positive wire first, taking care that the fan is in the "Off" position the whole time. Make sure that the motor is fully connected.

Step 4 - Replace the Cover and Test

Take the cover from your assistant, and replace it over the outside of the fan. Some fan covers need to be positioned accurately before they will fit, so if you are having trouble sliding the cover back on, try rotating it to the left, and try again. Once the cover is back on the fan, replace the screws, making sure that they are all accounted for, and then descend from the ladder. Only when you are clear of the fan should you try using it again. If the fan does not work, make sure that it is in the "Off" position before you remove the cover again.