My humidifier aprilaire 760 will not turn on. I do hear the click when I turn the knob on the thermastate but the unit stll doesn't turn on. All electric is turned on and the water supply is on.

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, ...
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the float may be bad or sticking allowing water to run continusly even when unit is off.

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

Normal 0 false false false MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Your Aprilaire Humidifier is designed to operate in conjunction with your furnace blower motor. Most installers wire a humidifier to operate when the furnace is calling for heat. To determine if your Aprilaire Humidifier is maintaining proper humidity, turn up the heat temperature 5 degrees above the current room temperature on your thermostat and set your humidifier control to call for humidity. The humidifier control is located on the cold air return duct. To set your humidifier control to call for humidity, turn the control dial to the off position and slowly rotate the dial until you hear a “click” on the control. You should also hear a click at the solenoid valve located on your Aprilaire unit. The humidifier control will have a click point at the current relative humidity level in your home. If the current relative humidity is 45% or the outdoor temperature is above 60F, the control will only operate the humidifier in the test mode.
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1. No click at the solenoid valve indicates an electrical problem. Contact your heating and air conditioning dealer to further check the electrical components of your Aprilaire Humidifier.

1. The click sound at the solenoid valve indicates there is electricity to the solenoid valve. By turning the dial of your humidifier control to a setting above the “click point” you should see water coming out of the drain line within a few minutes which would indicate your humidifier is working.

1. If the solenoid valve makes a click sound and there is no water draining from the unit, this would indicate the flow of water is being obstructed.

1. To determine if water flow is being obstructed, turn the dial of your humidifier control to the off position. The first location you would want to check for an obstruction would be at the saddle valve located on the water line supplying water to the humidifier. When checking the saddle valve, you want to make sure it is completely open. This can be done by turning the valve all the way to the left. If anything is clogged, it can be dislodged by turning the saddle valve all the way to the right and back to the left. Once this is done, turn the humidifier control dial above the click point and you should see water coming out the drain line.


If water is still not coming out of the drain, check the orifice and in-line strainer to make sure they are not clogged. The orifice is located in the tube on the discharge side of the solenoid valve and the in-line strainer is located on the inlet side of the solenoid valve. You may clear the orifice by inserting a needle through the small opening. Clean the strainer by running it under warm water to dislodge deposits or replace. After clearing and re-installing the orifice and strainer (be sure to double wrench all water connections), turn the humidifier control dial above the click point and you should see water coming out the drain line.

With the heat on, turn control knob back&fourth from test.U should here a click each time.If no click check hum transformer power.If it clicks flush out water supply pipe poss cloged.

A simple check you can perform on your aprilaire 760 is the following:
1) locate the two brown wires coming out of the 760 (these wires will be wired to tell the 760 to turn on when the hvac bower is on and the humidistat is calling for moisture).
2) temprarily disconnect the two brown wires from the external wiring and then short the wires together. All you're doing here is bypassing the your thermostat and bower-on indicator.

With the 70 unit plugged in to the wall outlet and the two brown wires connected together, both the fan and the solenoid valve (water inlet valve) should both be activated.

The humidifier should not turn on untill the furnace blower starts. Since the fan stays on. does the solenoid valve also stay on? If they both stay on you probably have a bad humidistat. If only the blower stays on then the circuit bourd in the humidifier is defective.
Good luck
HVAC Teacher

the 760 send power out the humidistat is just a switch if you touch the two brown wire coming outof the 760 the humidifier should come on if it doesnt and you had appiled power to those wire you probably shorted the 760 control board

HI would check the filter in side might need changing or cleaning clean out wter tray in side, it could be just a blocked filter , hope this helps