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My Aprilaire 700 humidifier will not turn on. Water will not run or the power fan will not turn on. What could be the problem?

If you can disconnect the wires from the humidistat that go to the humidifier (wires that go to the two brown wires that come out of the bottom of the humidifier) then plug the humidifier into a 110 volt outlet. Tie the two brown wires together that come out of the bottom of the humidifier together. The humidifier should come on and the water should flow. If it does come on then you probably have a 56 humidistat problem or outdoor sensor problem. If the humidifier doesn’t come on then you probably have a humidifier control board problem. Please make sure you are getting 24 volts to the humidistat on the R & C terminals by checking with a meter. We have a real good humidifier troubleshooting video below produced by ntsupply showing how to troubleshoot a solenoid valve. We sell the solenoid valves on the following page: Please click here if you are interested in the Aprilaire 4040 solenoid valve that we sell. We sell humidifier parts and supplies on the following page: Please click here if you are interested in seeing the humidifier parts and supplies that we sell.  If you have any questions please feel free to email us at: support@arnoldservice.com. We would love to have your business!