Tag: Attic Fan Thermostat

Dear Mr. Electrician:  How do I determine if I need an attic fan replacement? Answer:  You may not need a complete attic fan replacement.  It is often just a matter of replacing the fan thermostat, the attic fan motor, or sometimes both. NOTE: Some text links below go to applicable products on Amazon and eBay.  As an Amazon Associate, I earn from qualifying purchases.  Using my links helps to keep this website FREE. Table of Contents: How to Replace An Attic Fan Motor How I Wire An Attic Fan Attic Fan Replacement A simple test to determine if a complete attic fan replacement is needed is to disconnect the thermostat and then hard wire the fan motor directly to the power source.  If the motor works fine like that, a new thermostat is needed.  If the motor doesn't work, hums, or makes noise, you need a new attic fan motor. I have repaired and installed several attic fans as an electrician.  Although the work is pretty straightforward, it becomes challenging, given the working conditions.  A complete attic fan replacement is rarely needed. Replacing the roof-mounted attic fan motor involves climbing up in an attic with tools, safety gear, parts, water, and lighting.  Sometimes, I have had to put plywood on the ceiling joists and bring a ladder into the attic to reach the fan motor comfortably enough to work on it. Sometimes, I had to do this twice, once to diagnose the problem with the fan and get the model number and the second time to replace the attic fan motor.  Attic fan motors are proprietary and are not interchangeable, even though many look alike. Top Of Page It is essential to get the correct model number of the fan before searching for attic fan replacement parts.  The model number on the fan motor can help track down a replacement, but having the original fan manufacturer's name and model number is the best. The fan motor above had bad bearings and made a loud noise when turned on.  I disconnected the thermostat and wired the motor directly to test the motor.  This fan accumulated dust because the dryer vent duct up to the roof leaked air, and the fan sucked up the dust.  The dust inhibits airflow through the motor for cooling purposes.  The motor could overheat and fail prematurely. The fan model above has its thermostat mounted directly on the fan.  Other brands have the thermostat a short distance from the fan blades. CLICK HERE to See Attic Fan Motors On eBay  Top Of Page HOW I REPLACE AN ATTIC FAN MOTOR It begins with my work pants that have built-in kneepads and side pouches.  I also have a dust mask or a respirator to wear.  Sometimes, I wear my hard hat, but it can be inhibiting, depending on the working conditions.  Work gloves are also essential to keep from getting splinters when grabbing onto wood beams.  I wear a headlight; if there is no other light, I will bring a work light and cord up there. Though it may be summer and...