Hello,
Thanks for creating this forum and I hope someone can help. I have a Carrier HUMCCLFP1318 which I believe is an Aprilaire 700 that will not kick on when the furnace starts heating. Here are the facts:
This unit is using the Aprilaire 56 humidistat.
The humidistat is getting 24VAC off the accessory panel in the furnace. Reads around 27 VAC using a multimeter. This is connected to R C in the humidistat.
The humidifier brown wires are connected to H in the humidistat.
When I touch the brown wires together at the humidifier, the unit fan turns on and water flows. It works.
If I touch the R C wires and the H wires together at the humidistat, the fan starts and water flows. It works. When I did this, the Voltage at the brown wires near the humidifier reads 21 volts.
When the furnace kicks on for heating, I measured the voltage at brown wires near the humidifier and it reads 27 volts. During this same test, I measured the yellow that lead to the solenoid and it read 0 voltage.
This is connected to an auto sensor. I removed that and connected the manual resistor. No change in behavior.
I replaced the humidistat and see no change in behavior.
If I turn the humidistat knob to test mode, the unit kicks on and water flows. It works.
It will not kick on with the furnace and I am not sure why. I am wondering if the control board is bad and is not relaying at receiving 27 volts. Although, why would it kick on when it received 21 volts after touching the wires together at the humidistat.
Hope this is enough information to figure this out. Appreciate any feedback.
Thanks,
Aaron
Thanks for creating this forum and I hope someone can help. I have a Carrier HUMCCLFP1318 which I believe is an Aprilaire 700 that will not kick on when the furnace starts heating. Here are the facts:
This unit is using the Aprilaire 56 humidistat.
The humidistat is getting 24VAC off the accessory panel in the furnace. Reads around 27 VAC using a multimeter. This is connected to R C in the humidistat.
The humidifier brown wires are connected to H in the humidistat.
When I touch the brown wires together at the humidifier, the unit fan turns on and water flows. It works.
If I touch the R C wires and the H wires together at the humidistat, the fan starts and water flows. It works. When I did this, the Voltage at the brown wires near the humidifier reads 21 volts.
When the furnace kicks on for heating, I measured the voltage at brown wires near the humidifier and it reads 27 volts. During this same test, I measured the yellow that lead to the solenoid and it read 0 voltage.
This is connected to an auto sensor. I removed that and connected the manual resistor. No change in behavior.
I replaced the humidistat and see no change in behavior.
If I turn the humidistat knob to test mode, the unit kicks on and water flows. It works.
It will not kick on with the furnace and I am not sure why. I am wondering if the control board is bad and is not relaying at receiving 27 volts. Although, why would it kick on when it received 21 volts after touching the wires together at the humidistat.
Hope this is enough information to figure this out. Appreciate any feedback.
Thanks,
Aaron