Gas Code (NFGC) ANSI Z223.1-2002/NFPA 54-2002, Parts 7 and
10 in the United States and the National Standard of Canada,
Natural Gas and Propane Installation Codes (NSCNGPIC) CSA-
B149.1-00, Section 7 and Appendix C in Canada.
These furnaces are design-certified as Category I furnaces in
accordance with ANSI Z21.47a/CSAa 2.3-2001 and operate with a
non-positive vent static pressure to minimize the potential for vent
gas leakage. Category I furnaces operate with a flue loss not less
NOTES FOR FIGURE 24-31
1. Heat pump MUST have a high pressure switch for dual fuel applications.
2. Refer to outdoor equipment Installation Instructions for additional information and setup procedure.
3. Select the “ZONE” position on the two-speed heat pump control.
4. Outdoor Air Temperature Sensor must be attached in all dual fuel applications.
5. Dip switch No. 1 on Thermidistat should be set in OFF position for air conditioner installations. This is factory default.
6. Dip switch No. 1 on Thermidistat should be set inON position for heat pump installations.
7. Dip switch No. 2 on Thermidistat should be set in OFF position for single-speed compressor operation. This is factory default.
8. Dip switch No. 2 on Thermidistat should be set in ON position for two-speed compressor operation.
9. Configuration Option No. 10 “Dual Fuel Selection” must be turnedON in all dual fuel applications.
10. NO connection should be made to the furnace HUM terminal when using a Thermidistat.
11. Optional connection: If wire is connected, dip switch No. 1 on furnace control should be set in ON position to allow
Thermidistat/Thermostat to control furnace staging.
12. Optional connection: If wire is connected, ACRDJ jumper on furnace control should be removed to allow Thermidistat/Thermostat to
control outdoor unit staging.
13. Furnace must control its own high-stage heating operation via furnace control algorithm.
14. The RVS Sensing terminal “L” should not be connected. This is internally used to sense defrost operation.
15. DO NOT SELECT the “FURNACE INTERFACE” or “BALANCE POINT” option on the two-speed heat pump control board. This is
controlled internally by the Thermidistat/Dual Fuel Thermostat.
16. Dip switch D on Dual Fuel Thermostat should be set in OFF position for single-speed compressor operation. This is factory default.
17. Dip switch D on Dual Fuel Thermostat should be set in ON position for two-speed compressor operation.
Fig. 32—Variable Speed Furnace Control-ECM Blower Motor
A02018
Model Plug
Set up Switches SW1, 1
thru 8
A/C & Constant Air Flow
Switches
Status Code Light
Fuse, 3 Amp
24 VAC Output
Neutral Leads and
EAC 2 (Neutral)
12 Pin Inline
Connector
115 VAC Input
Transformer
Primary & 120
VAC to ECM
Motor
115 VAC Output to
HSI & Inducer
ECM Motor harness
Connector
Future Use
115 VAC EAC Input
(1.0 AMP MAX)
24 VAC Hum Output
(0.5 AMP MAX)
ACRDJ Jumper
OA
T
PL9
A B C D
PL4
HUM
A
CRDJ
PL7
W2
Y1
DHUM
G
Com
24V
W/W1 Y/Y2
R
COMM
LEDS
STATUS
CODE
FUSE 3-AMP
SEC-2 SEC-1
EA
C-2
NEUTRAL-L2
PL1
PL3
EA
C-1
1-AMP@115 V
A
C
L1
PL2
VS HSI HI LO
SW4
SW
-1
SW2
AC
SW3
CF
21
