24
To ensure proper unit grounding, the ground wire should run from
the furnace ground screw located inside the furnace junction box
all the way back to the electrical panel.
NOTE: Do not use gas piping as an electrical ground.
To confirm proper unit grounding, turn off the electrical power
and perform the following check.
1. Measure the resistance between the neutral (white)
connection and one of the burners.
2. Resistance should measure 10 ohms or less.
This furnace is equipped with a blower door interlock switch
which interrupts the unit voltage when the blower door is opened
for servicing.
NOTE: Do not defeat this switch.
24-Volt Thermostat Wiring
As a 2-stage furnace, the furnace integrated control module
provides terminals for both W1 and W2, and Y1 and Y2
thermostat connections. This allows the furnace to support the
following system applications: 2-stage heating only, 2-stage
heating with single-stage cooling and 2-stage heating with
2-stage cooling. Refer to the following thermostat wiring
diagrams for proper connections to the integrated control
module.
Low voltage connections can be made through either the right or
left side panel. Thermostat wiring entrance holes are located in
the blower compartment. The following illustration shows the
connections for a heat/cool system.
This furnace is equipped with a 40 VA transformer to facilitate use
with most cooling equipment. Consult the wiring diagram located
on the blower compartment door for further details of 115-volt
and 24-volt wiring.
NOTES:
■
For single-stage cooling applications, a jumper may be
required between Y1 and Y2 at the furnace control in order to
achieve the desired single-stage cooling airflow. Consult the
Blower Performance charts to determine if the required
single-stage cooling airflow can be delivered at low stage (Y1
input) or high stage (Y2 input). Additionally, use of ramping
profile and dehumidification features require a jumper
between Y1 and O and Y1 and DEHUM, respectively.
■
Thermostat R required if outdoor unit is equipped with a
Comfort Alert
TM
module.
Thermostat Wiring Diagram—Single-Stage Thermostat
Application
NOTE: Place jumper between Y1 and O for proper
dehumidification operation and proper ramping profile operation.
NOTE: To apply a single-stage heating thermostat, the
thermostat selector switch on the integrated control module must
be set on single-stage.
Thermostat Wiring Diagram—2-Stage Heating with
Single-Stage Cooling
NOTE: Place jumper between Y1 and O for proper
dehumidification operation and proper ramping profile operation.
Thermostat Wiring Diagram—2-Stage Heating with
2-Stage Cooling
NOTE: Place jumper between Y1 and O for proper
dehumidification operation and proper ramping profile operation.
Goodman 31
WARNING
To avoid the risk of injury, electrical shock or death, the
furnace must be electrically grounded in accordance with
local codes or, in their absence, with the latest edition of the
National Electric Code (NEC).
Goodman Important Note
Wire routing must not interfere with circulator blower
operation, filter removal or routine maintenance. A removable
plug connector is provided with the control to make
thermostat wire connections. This plug may be removed to
allow wire connections to be made to the plug and then
replaced. It is STRONGLY recommended that multiple wires
into a single terminal be twisted together prior to inserting
into the plug connector. Failure to do so may result in
intermittent operation.
IMPORTANT NOTE
A. Thermostat—single-stage heating
and single-stage cooling
B. Furnace integrated control module
C. Dehumidistat (optional)
D. Remote condensing unit
(single-stage cooling)
A. Thermostat—2-stage heating and
single-stage cooling
B. Furnace integrated control module
C. Dehumidistat (optional)
D. Remote condensing unit
(single-stage cooling)
A. Thermostat—2-stage heating and
2-stage cooling
B. Furnace integrated control module
C. Dehumidistat (optional)
D. Remote condensing unit
(2-stage cooling)
Y
R
R
Y
C
NEU
A
B
C
D
Y
R
R
Y
C
NEU
A
B
C
D
W1
W2
Y2
Y2
Y2
W2
W1
NEU
A
B
C
D
