18
To use a single-stage thermostat, turn off power to the furnace,
move the thermostat selection DIP switch to the OFF position.
Set the desired transition time by setting the transition delay
DIP switch to the desired ON/OFF position. Turn power back
on. Refer to the following figure.
3
4
Thermostat
Stage Delay
Move to the ON position
to select two-stage
thermostat or OFF to
select single stage
thermostat
Move to the ON position
to select Auto transition
delay or OFF for 5 minute
transition delay
Heat OFF Delay
DIP Switches
ON
OFF
S1
24 V
OLT
D
EHUMIDISTAT
W
IRING
The optional usage of a dehumidistat allows the furnace’s cir-
culator blower to operate at a slightly lower speed (85% of
desired speed) during a combined thermostat call for cooling
and dehumidistat call for dehumidification. This can be done
through an independent dehumidistat or through a thermostat’s
DEHUM terminal (if available). This lower blower speed enhances
dehumidification of the conditioned air as it passes through the
AC coil. For proper function, a dehumidistat applied to this
furnace must operate on 24 VAC and utilize a switch which
opens on humidity rise.
Refer to the “Thermostat Wiring Dia-
grams” figure for additional wiring details.
To install/connect a dehumidistat:
1. Turn OFF power to furnace.
2. To enable the dehumidify function on the integrated control
module, set the dehumidification ENABLE dipswitch from
OFF to ON.
3. Secure the dehumidistat neutral wire (typically the white
lead) to the terminal marked “DEHUM” on the furnace
integrated control module.
4. Secure the dehumidistat hot wire (typically the black
lead) to the terminal marked “R” on the furnace integrated
control module.
5. Secure the dehumidistat ground wire (typically the green
lead) to the ground screw on the furnace junction box.
NOTE:
Ground wire may not be present on all
dehumidistats.
6. Turn ON power to furnace.
Once the switch is set, the dehumidify function is enabled dur-
ing a
combination
call for cooling (T-Stat) and dehumidification
(DEHUM-Stat).
1
2
DEHUM
TRIM ENABLE
Move to the ON position
to enable dehumidification
ON
OFF
S5
F
OSSIL
F
UEL
A
PPLICATIONS
This furnace can be used in conjunction with a heat pump in a
fossil fuel application. A fossil fuel application refers to a com-
bined gas furnace and heat pump installation which uses an
outdoor temperature sensor to determine the most cost effi-
cient means of heating (heat pump or gas furnace).
A heat pump thermostat with
three stages of heat
is required to
properly use a two-stage furnace in conjunction with a heat
pump. Refer to the fossil fuel kit installation instructions for
additional thermostat requirements.
Strictly follow the wiring guidelines in the fossil fuel kit installa-
tion instructions. All furnace connections must be made to the
furnace two-stage integrated control module and the “FUR-
NACE” terminal strip on the fossil fuel control board.
115 V
OLT
L
INE
C
ONNECTION
OF
A
CCESSORIES
(H
UMIDIFIER
AND
E
LECTRONIC
A
IR
C
LEANER
)
HIGH
VOLTAGE
!
T
O
AVOID
PERSONAL
INJURY
OR
DEATH
DUE
TO
ELECTRICAL
SHOCK
,
DISCONNECT
ELECTRICAL
POWER
BEFORE
SERVICING
OR
CHANGING
ANY
ELECTRICAL
WIRING
.
WARNING
The furnace integrated control module is equipped with line
voltage accessory terminals for controlling power to an optional
field-supplied humidifier and/or electronic air cleaner.
The accessory load specifications are as follows:
Humidifier
1.0 Amp maximum at 120 VAC
Electronic Air Cleaner
1.0 Amp maximum at 120 VAC
Turn OFF power to the furnace before installing any accessories.
Follow the humidifier or air cleaner manufacturers’ instructions for
locating, mounting, grounding, and controlling these accessories.
Accessory wiring connections are to be made through the 1/4"
quick connect terminals provided on the furnace integrated control
module. The Electronic air cleaner hot terminal is identified as
EAC.
It is necessary to remove the protective tab on the board
cover to access the EAC Terminal.
The EAC neutral terminal
is identified as NEUTRAL. A line voltage humidifier may be
connected between one of the HUM contacts and NEUTRAL.
The other HUM contact must be fed from the L1 terminal.
All field wiring must conform to applicable codes. Connections
should be made as shown in the following figure.
