Connecting humidifier to Nest


Old 12-19-15, 09:36 AM
Thread Starter
Join Date: Dec 2015
Posts: 1
Received 0 Votes on 0 Posts
Connecting humidifier to Nest

I have a similar setup. I just recently purchased a 2nd gen nest. I have an air conditioner, an oil furnace and an Aprilaire 560 humidifier. I have everything working except the humidifier.

Here is the Pre-nest setup for the humidifier.

2 yellow wires come out of the solenoid for the humidifier (24 Volt solenoid) one is connected to a red wire, one to a white wire. The white wire travels into my furnace and is connected to a 24 volt transformer then continues up the wall and connects to a terminal on the humidistat control.

The Red wire goes into the furnace and appears to connect to the yellow wires on the furnace blower or the C terminal (Its hard for me to tell without ripping it all apart), the red wire then also continues up the wall and connects to the humidistat control.

Now, from the reading I have done, it seems I should connect one wire to the * on the nest and with this configuration I could leave the other wire disconnected (the red wire), and eliminate the humidistat control.

This doesn't seem to work, (at least I can't get any water out of my humidifier)

Please help, it would be appreciated.

Sponsored Links
Old 12-19-15, 09:54 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 59,077
Received 1,110 Votes on 1,030 Posts
Welcome to the forums.

I moved you to a new thread.

connected to the yellow wires on the furnace blower or the C terminal
I am not following you here. It's one or the other and the furnace blower is 120volts so no thermostat wiring should be connected to it.

However.... you may have a current sensing relay. It's a module that clips around one of the blower wires. It may have two yellow wires coming out of it. You'll need to check into that.

Basically one yellow wire from the humidifier connects to the * and the other connects to C.
There should be nothing else in the line.
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: