VisionPRO IAQ/EIM not controlling humidifier


Old 02-27-09, 10:15 PM
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Question VisionPRO IAQ/EIM not controlling humidifier

I've read most of the VisionPRO / Humidifier threads and am still struggling...

I just installed VisionPRO IAQ Model TH9421C1004 and it's companion EIM with an Outdoor Temp Sensor. Everything is working fine except the humidifier control.

The furnace is Carrier 58PAV and humidifier is AprilAire 550. The humidifier was working fine (before I started).

To install the EIM, I disconnected the humidifier from the furnace and from its old controller and abandoned those connections entirely.

I made the following new conections:
- EIM R/RC/RH jumped to EIM HUM1
- EIM HUM2 to SolenoidLead1
- SolenoidLead2 to EIM C
- the connections are tight and i have power

On the VisionPRO touch screen, when I press MORE and get to the humidification screen, I see the inside humidity level, but there are NOT any up/down arrows on the screen, irrespective of the furnace cycle.

What have i done incorrectly?

Old 02-27-09, 10:42 PM
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did you go to installer set up 370 and 372 and make sure they are configured correctly for Humidification?

Sounds like your wiring is correct..
you could check the Humidifier by powering it up off the transformer.

The factory default for 370 is 1 (internal sensor)
The factory default for 372 is E (auto discover) 0= off 1= Humid, no frost protection and 3= Humid, frost protection
Old 02-28-09, 06:42 AM
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YEs, the factory preset installer setup functions were as you suggested with 370=1 and 372=E.

Thanks for the tip to look more CLOSELY at the installer setup functions. My AprilAire550 is apparently NOT compatible with the Autodiscover feature and I needed to manually set function 372. A closer look at the manual has 2 asterisks that direct the reader to a page where the limitations of Autodiscover are noted.

I went ahead and manually set 372=3 (humidity with frost protection) and the humidity controls came alive on the panel. The unit appears to be working now.

Thanks very much for the help.
Old 02-28-09, 06:50 PM
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Any settings that shows "E", change it to a number value.

I'd suggest you to check the heating cycle (CPH) and set them to 3.

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