DO NOT connect furnace control HUM terminal to HUM
(humidifier) terminal on Thermidistat™, Zone Controller, or
similar device. See Thermidistat, Zone Controller, thermostat,
or controller manufacturer’s instructions for proper connec-
tion. A failure to follow this warning could result in fire.
NOTE:
A field-supplied, 115-v controlled relay connected to
EAC terminals may be added if humidifier operation is desired
during all blower operation.
Step 9— Venting
Refer to the national or local installation code such as NFGC in the
United States, or the NSCNGPIC in Canada for proper vent sizing
and installation requirements. Use the enclosed Installation In-
structions (Single-Stage Vent Tables for Category I Fan-Assisted
Furnaces) for a quick, easy reference.
After fully assembling the vent connector to the furnace flue collar,
securely fasten the vent connector to the collar with two field-
supplied, corrosion-resistant, sheet metal screws located 180° apart
and midway up the collar.
The horizontal portion of the venting system shall maintain a
minimum of 1/4-in. upward slope per linear ft and it shall be
rigidly supported every 5 ft or less with hangers or straps to ensure
that there will be no movement after installation.
Step 10—Start-Up, Adjustment, and Safety Check
GENERAL
NOTE:
Proper polarity must be maintained for 115-v wiring. If
polarity is incorrect, the furnace control status indicator light will
flash rapidly and furnace will not operate.
The furnace must have a 115-v power supply properly connected
and grounded. Proper polarity must be maintained for correct
operation. Thermostat wire connections at R, W, C
OM
-24V, and Y
must be made at the 24-v terminal block on the control board. The
gas service pressure must not exceed 0.5 psig (14-in. wc), but must
be no less than 0.16 psig (4.5-in. wc).
This furnace is equipped with a manual reset limit switch or
fuse link in the gas control area. The switch or fuse link opens
and shuts off power to the gas valve if a flame rollout or
overheating condition occurs in the gas control area. DO NOT
bypass the switch. Correct inadequate combustion air supply
problem, and reset the switch or replace the fuse link.
Before operating the furnace, check each manual reset switch for
continuity. If necessary, press the button to reset the switch.
The blower compartment door must be in place to complete the
115-v circuit to the furnace.
SEQUENCE OF OPERATION
Furnace control must be grounded for proper operation, or
control will lockout. Control is grounded through green wire
routed to gas valve and burner bracket screw. Connect
furnace ground wire to earth ground.
Using the schematic diagram shown in Fig. 11, follow the
sequence of operation through the different modes. Read and
follow the wiring diagram very carefully.
→
Fig. 10—Furnace Control
A00292
G
R
Y
W
Com
24V
HUM
3-AMP FUSE
HUMIDIFIER TERMINAL
(24-VAC 0.5 AMP MAX)
LED OPERATION &
DIAGNOSTIC LIGHT
HARNESS CONNECTOR
24-V TRANSFORMER SEC-2
SPARE-1
SPARE-2
EAC-1 (BLACK)
EAC-ELECTRONIC AIR CLEANER
TERMINALS (115-VAC 1 AMP MAX)
EAC-2 (WHITE)
115-VAC (L2) NEUTRAL
CONNECTION
24-V THERMOSTAT
TERMINALS
BLOWER SPEED
SELECTION TERMINALS
INDUCER MOTOR
CONNECTOR
115-VAC (L1)
POWER SUPPLY
HOT SURFACE
IGNITOR CONNECTOR
HEAT
COOL
BLOWER OFF DELAY
ADJUSTMENT SWITCH
SEC-1
TEST/TWIN
10
