Humidifiers and Dehumidifiers - Wiring Aprilia 400 into furnace

I just purchased an Aprilia 400 humidifier and wanted to verify my method of installation before I begin cutting. I do not have much room on my supply side of the furnace to mount the unit, so I was going to use the return side. So far, everything that I am reading suggests that that is okay and I should use hot water.

My main issue is wiring. I purchased the #50 relay, but after reading the posts on this forum, I'm not sure I actually need it.

Here is a picuture of my circuit board in my furnace.
http://www.smoovservices.com/dl/Integrated%20Board.jpg

According to my circuit board, do I use the "HUM" and one of the "Neutrals" to go to the transformer that supplies power to the Aprilia 400? Also, what does "EAC" stand for?

Yes, you may use the board instead of the A50 relay.

HUM will provide power any time the burners itself are running.

EAC stands for Electronic Air Cleaner. That can be used as well. That will provide power any time the blower is running. I like the EAC side since you can add humidity into the air when you just run the fan "ON" mode vs AUTO. And yes, you tie this to the transfromer.

Thanks, I feel alot better about doing the install now.

Keep us posted, or if you have any more question, let me know.

I'll let you know how the install goes. Hopefully I can by the store to get the water line and duct tubing that I need by the middle of the week. Thanks again for all your help.

Install is finished. No water leaks, and everything seems to be working. Thanks again for all of the help.

Glad to hear it worked out for ya.. Thanks for the update.