How to Replace an Attic Fan Thermostat

Attic fans with built-in thermostats are great. The thermostat keeps track of the temperature and turns the fan on and off when it's necessary. You don't have to lift a finger. On the other hand, if the thermostat breaks, the fan stops working altogether. Here's a rundown of how an attic fan thermostat works and how to replace one if it breaks.

Function of the Thermostat

An attic fan thermostat is an automatic monitoring mechanism that switches the attic fan on and off according to the changing temperature in the attic.

It turns the attic fan on when it reaches a certain temperature (ranging from 90 degrees F to 120 degrees F). This can be a factory preset or set by the homeowner. The other function is to turn or shut off the fan when it reaches the low preset temperature (usually 80 degrees F) or when there is a very high temperature (over 180 degrees F), indicating that the house may be on fire.

The thermostat ensures that a set temperature range is maintained at all times. When you discover that the thermostat stops working, what should you do?

Replacing a Defective Thermostat

If you observed that the attic fan is not switching off and on at the preset temperatures, the attic fan thermostat might not be functioning properly, and you might need to replace it. These easy steps will guide you to replace a defective thermostat:

Turn off the attic fan and remove the cord from the outlet. To be totally safe, you might want to turn off the main switch or breaker to avoid getting electric shocks from accidentally touching live lines or wires. Look for the thermostat casing and, using a screwdriver, open it carefully.

With a writing pad, take note of the temperature settings, power rating of the thermostat, and fan capacity (in cubic feet per minute) for reference purposes. This way, you can duplicate your old settings when you install the new thermostat.

Take note of the wiring of the thermostat. Remove the wiring carefully. Install the new thermostat. Connect the wiring as it was when you removed it. Put the casing back with the screwdriver. Connect the power cord back to the convenience outlet.

Switch on the fan. See if it switches on and off when the preset temperatures are reached. This will indicate that the thermostat is now functioning properly. If it is not, go over the installation procedures again, to make sure you didn't skip or botch a step.

Other Causes

It is also possible that the thermostat is okay and stopped because of other factors. Consider checking the power connections to make sure electricity is being supplied to the thermostat. It is possible that other devices are interfering with it.

Call the Expert

If you feel that you do not have the necessary skill to do the replacement, you can call an electrician to do the job for you. He will be able to check the root cause of the problem and fix it with less time and effort. Always remember to play it safe.