How To Test Attic Fan

Step 1 test the fan motor.

How to test attic fan.

Locate the thermostat casing and open it using a screwdriver. Turn the attic fan off and unplug the motor from the thermostat. If the fan turns on the motor is still good. You simply add up the nfas of all your vents and divide that number by the area of the attic to determine whether you re within the 1 150 ratio.

Also note down the power rating and the fan capacity in cubic feet per minute. If the fan comes on you know that the problem lies with the fan thermostat. Test the first set of wires. Once done test that the motor still works by plugging the motor into an extension cord that is connected to an outlet.

Attic fan thermostat if your fan has a thermostat turn the fan on and off bypassing the thermostat. If the fan comes on you have an electrical problem in the circuit the attic fan is on. Also check the wire connections at the fan at an electrical junction or at an outlet box. Most fans have an on off switch that bypasses the fan s thermostat.

If however the fan still doesn t turn on the problem is most likely with the fan motor or the thermostat. It s best to hire an electrician to deal with electrical problems. If the attic fan is plugged into an outlet use a voltmeter to make sure that the outlet is working. The white wire is called the run wire.

Step 2 test the thermostat. Switch off the power of the attic fan and remove the power cord. Now is the time to test the white brown and white wires. If it automatically trips again after resetting it you may have a short in the wires along the circuit.