Attic Fan Motor Not Working High Speed

The user chooses a fan speed by selecting a speed which then connects one of the resistors in the blower resistor pack.

Attic fan motor not working high speed.

Does the speed switch look like the silver handle coming out of the plate. 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. These are the common causes. If this doesn t fix the problem a burned out fan motor may need replacing.

A two speed attic fan should just need a basic toggle switch. Repairs are generally impractical. Little or no airflow. 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.

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. 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. Look at the circuit breaker or fuse box to see if a switch has flipped. Other possibilities include damage to the wiring or a switch best repaired by an electrician.

Check that a whole house fan is receiving electrical power when it doesn t work at all. The blower resistor is connected in series to the blower fan motor. If there is any damage to the belt replace it with a new one. Attic exhaust fans power ventilators we usually simply replace the entire unit.

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. It selects one fan winding for slow or the other for high. Try tapping on that relay to see if it is stuck.

If the motor is working but the fan blades are not moving the problem may be the belt. This means that the current running through the blower motor and its speed is therefore controlled by the resistor value. Attic fans can sometimes start making noise whether it s humming rattling or making some other annoying noise. Blower resistors are made of.

Attic fan not turning on.