Switching out a GeneralAire M3 Humidistat to a GFX4
I switched out the MC myself but I seem to be having a problem getting my GFX4 to work Keeping in mind that the M3 is purely mechanical and the GFX is digital. I've put the two wires into Hum1 and Hum2 as the instructions seem to suggest but no power which I sort of get but I also sort of assumed that those were low voltage. Too much assuming on my end. I see the ACL (R) and the ACC (C) and they are 24 volts so I'm thinking I should be putting the red wire into one of those maybe? Or should I be using both the ACL and the ACC?
I just got a new furnace and humidifier and am concerned about blowing something up.
That GFX4 is pretty pricey and I'm a little disappointed that it's not more user friendly.
I use the Aprilaire humidistats. A little more bang for the buck.
I don't allow the humidistat to control the blower in my installs so I don't use G or Gf.
The left diagram is the one they want you to follow. That requires the furnace to switch 120v to the transformer which can be a little tough. Some furnace boards have a 120v HUM terminal which is where the transformer would connect. If you have that.... follow that.
Many furnaces don't have a HUM terminal. Some have a 24v HUM terminal. That would be ideal.
In the second diagram.... the red and blue connect to the furnace board R and C. You need a jumper from C to H. The other H goes to the solenoid. The hum terminals are not powered.... they are just a switch. The second solenoid wire goes to the furnace board W or if you have a 24v HUM terminal... it can go there.
If you have any board questions... post a picture of it and the part number off of it.
I installed an Aprilaire700M (does not start when shorting out the wires so its the newer one) I am having issues with the wiring. I have the PEK kit installed with my ecobee. I do have one extra wire in the wall so i used that and connected it to the ACC+. then ran the other wire to the C on the furnace. Needless to say its not working. What am i missing? Do i need to run my empty wire to C and eliminate the PEK? Then run a new wire and hook it up to ACC+ and ACC-? Please help.
I have been reading through every thread I could find today to better understand how to wire the AprilAire 700 with the Ecobee. I feel like I found most of what I need help with, but not entirely.
I have the Ecobee Premium and that is installed and working correctly (no PEK). I just installed the AprilAire 700 a few days ago...except the wiring. I want to have the Ecobee control the humidifier.
I have a spare brown wire at the stat not in use. I believe this should connect to ACC+ on the stat and the other end to 1 yellow wire to the solenoid. The remaining yellow wire on the solenoid should go to the C terminal on the furnace.
On the newer 700, I am not sure how I need to wire up the brown wires from the humidifier. Shorting them is for the older model, if I understood correctly? Where am I connecting the brown wires?
Thanks,
Mark
01-30-23, 10:33 AM
Keeping in mind that the M3 is purely mechanical and the GFX is digital. I've put the two wires into Hum1 and Hum2 as the instructions seem to suggest but no power which I sort of get but I also sort of assumed that those were low voltage. Too much assuming on my end. I see the ACL (R) and the ACC (C) and they are 24 volts so I'm thinking I should be putting the red wire into one of those maybe? Or should I be using both the ACL and the ACC? 
Keeping in mind that the M3 is purely mechanical and the GFX is digital. I've put the two wires into Hum1 and Hum2 as the instructions seem to suggest but no power which I sort of get but I also sort of assumed that those were low voltage. Too much assuming on my end. I see the ACL (R) and the ACC (C) and they are 24 volts so I'm thinking I should be putting the red wire into one of those maybe? Or should I be using both the ACL and the ACC? 
