How to Troubleshoot an Aprilaire 760 - No water / No Fan

Old 02-12-17, 11:40 AM
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How to Troubleshoot an Aprilaire 760 - No water / No Fan

Hi All, I have an Aprilaire 760 that's not working. I had the saddle valve replaced with a ball valve and we verified that water is getting to the solenoid. The solenoid makes a barely audible click shortly after the heat kicks on, but only a trace of water has made its way to the water pad. I'm pretty sure the solenoid is shot, but I'm unclear where to measure to see if the 24 volts is showing up? The two yellow solenoid wires run into the unit and the only exposed (brown) wires are from the thermostat. With the unit open, I noticed that the fan never kicks on, but maybe this is by design?

Should I just order a new solenoid and hope for the best?
Old 02-12-17, 01:15 PM
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If you can't measure volts then touch the top part of the solenoid, if it feel warm you have 24V.
Old 02-12-17, 04:20 PM
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Welcome to the forums.

exposed (brown) wires are from the thermostat.
Did you mean humidistat ??

You have a fan forced humidifier and is a little confusing to diagnose. That unit plugs into 120vac and has its own internal 24vac transformer. That one should make an internal click when the two brown wires are shorted together.

What do you get when you measure the AC voltage across the brown wires with them not connected ?

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See if you have this board inside the unit.............
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