31
441 01 2101 05
Specifications are subject to change without notice.
START
−
UP, ADJUSTMENT, AND SAFETY
CHECK
Step 1 — General
FIRE HAZARD
Failure to follow this warning could result in personal
injury, death and/or property damage.
This furnace is equipped with manual reset limit
switches in the gas control area. The switches open
and shut off power to the gas valve if a flame roll
−
out
or overheating condition occurs in the gas control
area. DO NOT bypass the switches. Correct problem
before resetting the switches.
!
WARNING
1. Maintain 115
−
v wiring and ground. Improper polarity
will result in status code 10 and no furnace operation.
2. Make thermostat wire connections at the 24
−
v terminal
block on the furnace control. Failure to make proper
connections will result in improper operation. (See
3. Gas supply pressure to the furnace must be greater
than 4.5
−
In. W.C. (0.16 psig ) but not exceed 14
−
In.
W.C. (0.5 psig).
CUT HAZARD
Failure to follow this caution may result in personal
injury.
Sheet metal parts may have sharp edges or burrs.
Use care and wear appropriate protective clothing,
safety glasses and gloves when handling parts and
servicing furnaces.
CAUTION
!
4. Check all manual
−
reset switches for continuity.
5. Install blower compartment door. Door must be in place
to operate furnace.
6. Setup switch descriptions The two
−
stage furnace has
DIP switches used to select thermostat staging and
heat off delay timings. For switch locations on Furnace
control board, See Figure 33 and Figure 55.
7. Setup switch descriptions
−
See Table 10.
Table 10 – Two
−
Stage Furnace Setup Switch Description
SETUP
SWITCH NO.
SWITCH
NAME
FACTORY
POSITION
DESCRIPTION
OF USE
SW1-1
Thermostat Type
OFF
When OFF, allows Two-stage operation with a single stage thermo
stat. Turn ON when using two-stage thermostat to allow Low Heat
operation when R to W/W1 closes and High Heat operation when R
to W/W1 and W2 close.
SW2-2
Heat OFF delay
OFF
Control heat OFF delay time. Used in conjunction with SW1-3.
See Table 14.
SW3-3
Heat OFF delay
ON
Control heat OFF delay time. Used in conjunction with SW1-2.
See Table 14.
Table 11 – Two
−
Stage Furnace Blower OFF Delay Setup
Switch
DESIRED HEATING MODE
BLOWER OFF DELAY (SEC.)
SETUP
SWITCH
SW1-2
SETUP
SWITCH
SW1-3
90
OFF
OFF
120 *
OFF
ON
150
ON
OFF
180
ON
ON
* Factory setting
Step 2 — Start
−
Up Procedures
FIRE OR EXPLOSION HAZARD
Failure to follow this warning could result in personal
injury,
death, and/or property damage.
Never purge a gas line into a combustion chamber.
Never test
for gas leaks with an open flame. Use a
commercially
available soap solution made
specifically for the detection of
leaks to check all
connections. A fire or explosion may result causing
property damage, personal injury or loss of life.
!
WARNING
ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury, or death.
Blower access door switch opens 115
−
v power to
control. No component operation can occur unless
switch is closed. Caution must be taken when
manually closing this switch for service purposes.
!
WARNING
1. Purge gas lines after all connections have been made.
2. Check gas lines for leaks.
3. To Begin Component Self
−
Test:
Remove blower access door. Disconnect the
thermostat R lead from furnace control board. Manually
close blower door switch. Short (jumper) the C terminal
on control to the TEST/TWIN 3/16
−
in. (8 mm)
quick
−
connect terminal on control until the LED goes
out (approximately 2 sec). Gas valve and humidifier will
not be turned on. Remove jumper from terminals. (See
NOTE
: The furnace control allows all components, except
the gas
valve, to be run for short period of time. This feature
helps
diagnose a system problem in case of a component
failure.
Component test feature will not operate if any
thermostat signal is
present at the control.
Refer to service label attached to furnace or See Figure 51.
Component test sequence is as follows:
