[kyletornquist]

hi,

I came across this board after going a rabbit hole on google, which started from cleaning up some dripping water from the bottom of the Aprilaire 600 housing unit. We've had an ecobee4 installed for several years now. When I initially installed it, I never gave thought to the humidifier control as I just got used to adjusting it during the winter and turning it off during the summer. It is evident now that it would be a lot better to have this on the fly adjustment from the smart thermostat. I started looking at the wiring I have and the wiring schematic and I am either thoroughly confused or overthinking it.

I believe I have a 1-wire set-up; however, I am really looking to avoid having to run another thermostat wire back to the ecobee. I've tried finding the routing up from the basement to the thermostat and it would not be easy to pull.

Here is a pic of the thermostat pulled off the wall so you can see the current wiring. I do not have any extra wires available.

The next three pictures show the wiring going from the furnace control board to the humidstat:
- There is one brown wire with 5 smaller wires running from the furnace control board to the humidifier control board and humidistat.
- The white wire from this bundle is connected from the humistat to the 'Y' terminal on the furnace control board.
- The blue wire that is providing the power is running from the 'C' terminal on the furnace control board, it is then spliced and connected with wire nuts to the solenoids for the humidifier and then continues up to the humidistat.

At this point, I am just looking for some direction as to how this needs to be rewired. Thanks!

 

[surferdude2]

- The white wire from this bundle is connected from the humistat to the 'Y' terminal on the furnace control board.

I think you meant it is connected to the W terminal. That would be the correct way to wire it if you only want the humidifier to operate in the heat mode, which is standard practice.

That begs the question of what will you gain by running an additional wire to the Ecobee since it's already being contolled adequately, assuming all the other wiring is correct.