Aprilaire 700 humidifier properly wired to outside sensor, to humidifier solenoid/fan and furnace. Works properly in test mode for 1 minute as stated in instructions. Solenoid/fan, water flow does not come on in any setting. I notice when juggling wiring going to control that the water panel change indicator and the red diagnostic light flickers off and on. Wiring to all terminals firm. Could I have a bad Humidifier control unit?
If humidifier was wired into thermostat circuit for power instead of seperate transformer , this can happen. you need to see if you voltage going to the solenoid valve. if you do , and it isn't opening, the valve is bad . this is assuming that it is using a # 50 relay to come on only when the fan runs . . make sure the water valve is open
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It sounds like it is just miswired. The low voltage wiring off the humidistat should be on W and C on the circ. board at the furnace. If you have it on R and C then it will power it constantly regardless if the heat is running or not. W is only energized on a call for heat which is typically when you want that type of humidifier to run
It appears your Aprilaire model 700 is wired to only operate when your HVAC fan is operated by your thermostat. Your HVAC installer can wire the humidifier control to operate the humidifier during a heat call, fan call or to turn on the fan when there is a need for humidification. Please contact your HVAC installer to have them change the wiring.
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if you mean your aprilaire humidifier isn't working then open the cover and remove the 4 screws on the fan motor mount inside and check for voltage at the transformer input 120 volts and output 25.5 volts a.c., then check the control board wherever you have it located on the furnace or upstairs and make sure yhe humidity level is set high enough to make the unit run(you will hear the water solenoid click on the furnace below the aprilaire unitwhere the water line is if its working correctly),then check the humidistat on the outside of the building as they can go bad
without using a meter? OK take the water line loose from the humidifier that connects to the solnoid. Turn the humidifier on or raise the humidity and water should flow. Keep in mind that if wired correctly the humidifier will only work when your furnace is running although some can be wired to bring on your furnace. You should hear or feel the click if no water comes out you may have no water flow as these valves are pretty durable and seldom fail
if it works in the test mode then it should be okay but you can get a humidity gauge from radio shack and set in the house to see how high or low its is. the humidifier is only going to give a max of 45% humidity
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.
When your unit is on normal the outside unit works and the inside only the fan runs. your heat pump does not remove any humidity when it operates so the installation cotractor did not wire it to operate then. you can change the wiring on the humidifier to operate all the time by wiring it to the fan (g) terminal then it should work just turn it all the way to the lowest humidity when you are in cooling mode.
I had this problem several years ago. In order for the water to flow, the outside temperature sending unit must indicate to the controller that it is less than 60F. If not, the unit will not operate outside of test mode. Check the temp outside where your sending unit is (could the sun be heating that side of the house?) and ensure that the circuit to the sending unit is working. I had a bad wire splice inside a wire nut stopping the circuit. Took me a long while to figure it out.
If the outside temp and your sending unit circuit is ok, I wish you luck on your troubleshooting.