Honeywell TrueSTEAM Guide D'installation page 42

Wiring Multiple TrueSTEAMs to One Humidity Control
Conventional
Thermostat
1
G
R
GT R C
GF
R
C
HUM
HUM
1 2 3 4 5 6
On
Off
TrueSTEAM
40
Y
W
C
R
GT GF
R
R
C
C
HUM
HUM
1 2 3 4 5 6
On
Off
TrueSTEAM
Separate Humidity
Control
Ensure thermostat isolates Y from G.
1
All Honeywell Prestige, VisionPRO, and
FocusPro thermostats do this.
R C W Y
G
R
C
M29641
TrueSTEAM Humidification System 69-2285EF—01