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mooredan · Jan 30, 2006, 07:09 PM

I have an Bryant Evolution system installed. This is the same as a
Carrier Infinity system. This consists of a 355MAV furnace, a 598B a/c
And SYSTXBBUID01 Evolution control.

Also installed in this system is a Honeywell Y8150 ventilator and a
Honeywell HE440 steam humidifier.

The evolution control is a recent addition to the system replacing a
Honeywell 8320 thermostat.

Previously, either the humidifier or ventilator could turn on the
Furnace fan. (by applying 24VAC to the G terminal of the furnace's
Control board).

After installing the control, which uses the furnace's data port on the
Control board, a call to turn on the fan by either of these components
Is ignored. However, the furnace and a/c operates normally with the
Evolution control.

Does anyone know what's going on here? Does hooking up the control
"lock out" the traditional thermostat connection controls? How can I
Get the ventilator or humidifier to turn on the fan in this
Configuration?

Thanks

Dan

Followup:

I have confirmed that when either the humidifier or ventilator wants
The fan to come on, they do put 24VAC on the "G" terminal. However, the
Fan does not come on.

If you're familiar with this system, you'll know that the control does
Not connect to the traditional furnace terminals G/W/Y/... but connects
To the furnace's data port (4-wire) on the system board.

It seems that the presence of a control (versus a traditional
Thermostat) is locking out (ignoring) the G terminal.

My question is does anyone have any experience with this system with
This type of configuration and if so, how can I get the an auxiliary
Piece of equipment to successfully make a fan call?

Dan

labman · Jan 30, 2006, 09:05 PM

Rather than waiting for an answer here, you may be better off with Bryant's or Honeywell'stech service or web site.

The79Bomb · May 5, 2008, 02:46 PM

The Humidifier is connected to port c and port "hum" on the control board in the furnace. I believe the thermostat is supposed to control the Humidifier using it's own humidistat not the other way around. It may be that the thermostat believes there is no Humidifier present. When you first configure the thermostat it asks for the presence of a fresh air unit and Humidifier and you have to set these to yes or no. check the thermostat manual and make sure these are set to yes.
Yours, Tim