My aprilair's humidifier motor began to make loud squealing noise

Yeah they do need to be replaced from time to time. Make sure you get a water test kit and check your water hardness. You may need a whole home water filter if it is outside of normal ranges. A pretty easy DIY project and relatively inexpensive at the big box stores

I have seen some humidifiers do this becuase of high water pressure. Try closing and opening the saddle valve and see if it helps at all.

Hello, usually when you hear a squeeky sound coming from humidifier it is the bearings on the motor, the only option is to replace the motor for the humidifier. I will post a link to a aprilaire store that carries motors for humidifiers. www.aprilairehumidifierparts.com

The model 550 is a bypass humidifier that does not have any working parts located within it. The squeaking noise that you are hearing is most likely not associated with the humidifier. If turn the dial on your humidstat all the way off, does the squeaking noise continue to occur? When you deactivate the humidifier by turning the dial on the humidstat to the lowest setting or off, and the noise continues to occur that is being produced by another product other than your humidifier.Please respond if issue is not resolved.

Try closing damper slightly between humidifier and furnace????

yes it should be bypass but solenoid could be trying to open but the voltage to it may be to low if you have 24v ac power at the 2 small wires. but to change shut down power to furnace and water to humidifier.you loosen the 2 compression nuts unwire they cant be reversed so dont worry then 2 mounting screws then reverse to install

A bad circuit board should not make any noises. A bad solenoid valve could make a loud buzzing noise. If the noise is a squealing noise then you have defective bearings in the blower motor.
If you disconnect the low voltage wiring from the solenoid valve and you still hear the noise, then its not the solenoid valve.

We recently had the same problem. After cleaning both the furnace filter and the humidifier water panel, the clicking noise (electric air filter) and the loud bang went away.

Try turning the water valve going to the soleniod down. There may be too much pressure. You may have to replace solenoid one more time after making the adjustment.

Not sure what type of humidifier you have but if is a power humidifier like the April 700 or 760 they do have a blower motor and it may be the fan blade is broken.But if you have a bypass humidifier is posible that your water solenoid may be making noise because of to much water pressure there is not much to a bypass humidifier, you may want to close the water supply valve a little at a time se if the noise goes away.