How do I stop the fan from making noise?

Motors humming are indicative of the start / run capacitor failing or the motor shaft is sticking. Get the the motor and see if it spins freely? It may need lubrication or the capacitor replacing. The purpose of the capacitor is to give the motor a jolt to get it going.

https://www.google.com/search?q=Essick+H12+400

..

There could be several reasons why a humidifier stops running after refilling it with water. One of the most common reasons is that the humidifier's float switch is stuck in the "low water" position, which prevents the humidifier from turning on even after refilling it with water . Another reason could be that the humidifier's water level sensor is malfunctioning, which causes the humidifier to stop running even when there is enough water in the tank/

If you have a whole-house humidifier, it could be that the humidistat is set too low, which causes the humidifier to turn off even when there is enough water in the tank 1. Alternatively, if you have a portable humidifier, it could be that the unit's motor has burned out or that its fan has stopped working .

To troubleshoot this issue, you can try cleaning the float switch or replacing the water level sensor if they are damaged. If you have a whole-house humidifier, you can try adjusting the humidistat to a higher setting. If you have a portable humidifier, you can try replacing its motor or fan

Sounds like the high pitched noise is coming from the solenoid valve which allows water to enter the humidifier. Typically when the water pressure is too high, it causes this high pitched sound at the solenoid valve. You can adjust the water pressure a little at a time and see if it helps, just make sure you’re getting enough water across the water panel.

Some helpful videos in the link as well as text articles and a link to a previously answered question on Fixya.

https://www.google.com/search?q=Aprilaire+760+making+strange+sound

It may be too high a water pressure for the solenoid.

Aprilaire Humidifier, too powerful a solenoid? Vent ducts noise.

https://www.houzz.com > discussions > aprilaire-humidifie...
The noise might be caused by having the water pressure up too high for the solenoid. Try backing off the water supply until the sound goes away. Hopefully, ...
..

no info generic answer ---check fan and compressor

Hello, water not reaching the humidifier can be caused sediment buildup in the strainer of the solenoid valve, a faulty solenoid valve, sediment at the saddle valve, or no power to the solenoid valve. The fan will run continously if the relay that engages the fan is stuck as it is gettimg a constant 120 volts.

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.

Sounds like your motor bearings are going bad. If at all possible lubricate the motor bearings using a few drops of a NON detergent oil. If the motor has sealed bearings with no oil ports then you should replace the blower motor.
Good luck

theholts220 - Sounds like they needed to install a bit larger transformer . You can also buy a A 50 Sensing relay that attaches to the wires for your motor and when you turn on the furnace it will allow the power to go to the humidistat. Very strange though they do not use a lot of power. Check and make sure the wires are not pinched or touching metal somewhere.


TLuzzo - The humidistat seems to be working when you turn it down. The wires for the solenoid should be hooked up to your furnace circuit board. The instruction manual will tell you where. If you dont have a spot on your circut board the A 50 sensing reley is they way to go. They are inexpensive

On my water wheel several parameters must be met. 1. Power on, cord plugged in. 2. Water in tank, the float arm needs to move to indicate water present, the red light on the dash indicates no water. 3. Humidity controll set higher than the room atmosphere humidity, clockwise is higher on mine. 4. The fan speed selecter must be on either high or low, the fan won't run unless one position is selected. I hope this helps