Installation guide
Installation Guide
69-2307—01 16
WIRIng
12
Wire the humidifier according to the diagram that applies to your humidity 
control.
Follow this diagram if using a mechanical 
humidistat.
HVAC
RECOMMENDED 
AIR FLOW 
SWITCH (AFS)
MECHANICAL
HUMIDISTAT
HVAC
POWER
MASTER
THERMOSTAT
HUM 
HUM 
GYWRRc
GYWR C
HUMIDIFIER - INTERNAL
24V
24V
HUM
HUM
C
GT
R
RT
GF
EXT
M29029
Factory 
installed 
jumper
If AFS is used, ensure 
DIP 5 is in ON position.
Follow this diagram to wire Automatic Digital 
Humidistat for manual operation.
Set the digital humidistat ISU parameter 10 to 1, and 
ISU 25 to 2.
A
For auto-operation: also wire W and G to thermostat 
W and G.
B
HVAC
DIGITAL HUMIDISTAT
THERMOSTAT
HUM 
HUM 
R
C
GYWRRc
GYWRC
24V
24V
HUM
HUM
C
GT
R
RT
GF
EXT
RECOMMENDED
AIR FLOW 
SWITCH (AFS)
M29030
HVAC
POWER
MASTER
HUMIDIFIER - INTERNAL
Factory 
installed 
jumper
If AFS is used, ensure DIP 5 is in ON position.
A
B
Follow this diagram if using a blower fan dedicated to the humidifier (a fan separate from the HVAC 
equipment, as in hydronic or cooling-only applications).
24V
24V
HUM
HUM
C
GT
R
RT
GF
EXT
HUMIDISTAT
HUM 
HUM 
HAC 
HAC 
MECHANICAL
HUMIDISTAT
HUM 
HUM 
HAC 
HAC 
RECOMMENDED
AIR FLOW SWITCH
(AFS)
HUMIDIFIER - INTERNAL
HVAC
120 VAC
RELAY
RED
BLACK
L1
L2
120
VAC
AT120
RC
M29031
HVAC POWER MASTER
Remove Factory 
installed jumper 
(R/RT)
If AFS is used, ensure DIP 5 
is in ON position.










