Attic Fan Motor Not Working High Speed

This means that the current running through the blower motor and its speed is therefore controlled by the resistor value.

Attic fan motor not working high speed.

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. 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. These are the common causes.

When running at a high speed setting does the attic fan run hard or sluggishly. 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. Does the speed switch look like the silver handle coming out of the plate. A two speed attic fan should just need a basic toggle switch.

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. Other possibilities include damage to the wiring or a switch best repaired by an electrician. Repairs are generally impractical. 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.

Little or no airflow. Look at the circuit breaker or fuse box to see if a switch has flipped. Remove the outer casing of the attic fan and check to see if the belt is sagging cracked worn or broken. If this is not your issue the next thing in line is the high speed relay mounted on the front of the hvac box behind the accumulator.

Blower resistors are made of. Attic exhaust fans power ventilators we usually simply replace the entire unit. You can fix this issue by turning down the settings or checking that the fan is getting enough air. If the motor is working but the fan blades are not moving the problem may be the belt.

If this doesn t fix the problem a burned out fan motor may need replacing. Attic fans can sometimes start making noise whether it s humming rattling or making some other annoying noise. The user chooses a fan speed by selecting a speed which then connects one of the resistors in the blower resistor pack. If there is any damage to the belt replace it with a new one.

Check that a whole house fan is receiving electrical power when it doesn t work at all.