Attic Fan Motor Not Working High Speed

If this fan has a timer and or a variable speed switch repairs are sometimes possible if the fault lies in one of the switches and not the motor.

Attic fan motor not working high speed.

The blower resistor is connected in series to the blower fan motor. A two speed attic fan should just need a basic toggle switch. Attic fans can sometimes start making noise whether it s humming rattling or making some other annoying noise. Attic exhaust fans power ventilators we usually simply replace the entire unit.

Does the speed switch look like the silver handle coming out of the plate. It selects one fan winding for slow or the other for high. Remove the outer casing of the attic fan and check to see if the belt is sagging cracked worn or broken. If it is rotating slowly or not producing a lot of air in the high speed setting you may have a problem with the exhaust or intake.

If this doesn t fix the problem a burned out fan motor may need replacing. Try tapping on that relay to see if it is stuck. Parts can come loose or erode from high amounts of fan usage while turning the speed up to high can cause a persistent loud hum. Blower resistors are made of.

You can fix this issue by turning down the settings or checking that the fan is getting enough air. The user chooses a fan speed by selecting a speed which then connects one of the resistors in the blower resistor pack. Your attic fan may not be turning on because of an electrical problem like a tripped circuit breaker a blown fuse or a bad connection. This means that the current running through the blower motor and its speed is therefore controlled by the resistor value.

Little or no airflow. Other possibilities include damage to the wiring or a switch best repaired by an electrician. Look at the circuit breaker or fuse box to see if a switch has flipped. These are the common causes.

If the attic fan isn t turning on it could be an electrical issue a problem with the thermostat or the motor of the fan that s not working. When running at a high speed setting does the attic fan run hard or sluggishly. Check that a whole house fan is receiving electrical power when it doesn t work at all. Attic fan not turning on.

Repairs are generally impractical.