Bryant 581J-17-28 Service And Maintenance Instructions page 42

Check Unit Operation and Make Necessary
Adjustments
NOTE: Gas supply pressure at the gas valve inlet must
be within specified ranges for the fuel type and unit size.
See Tables 9, 10, 11, and 12.
1. Shut off all electrical power supply to the unit and in-
stall a lockout tag.
2. Close the manual gas shutoff valve located on the gas
supply line.
3. Remove the manifold pressure tap plug from the man-
ifold and connect a pressure gauge or manometer. See
Fig. 54.
4. Turn on the electrical supply.
5. Open the manual shutoff valve, then turn on the unit
main gas valve.
6. Set the room thermostat to call for heat. Verify high−
stage heat operation before attempting to adjust the
manifold pressure.
7. When the main burners ignite, check all fittings, man-
ifold, and orifices for leaks.
8. Adjust the high−stage pressure to the specified setting
by turning the plastic adjustment screw clockwise to
increase pressure, and counterclockwise to decrease
pressure.
9. Set the room thermostat to call for low−stage heat.
Adjust the low−stage pressure to the specified setting.
10. Replace the regulator cover screw(s) when finished.
11. With the burner access panel removed, observe the
unit heating operation in both high stage and low
stage operation. Observe the burner flames to see if
they are blue in appearance, and that the flames are
approximately the same for each burner.
12. Turn off the unit, remove the pressure manometer and
replace the 1/8 in. pipe fitting on the gas manifold.
See Fig. 52.
Burner Ignition
The unit is equipped with a direct spark ignition 100%
lockout system. An Integrated Gas Unit Controller (IGC)
is located in the control box. See Fig. 55. The IGC
contains a self−diagnostic LED (light−emitting diode). A
single LED (see Fig. 57) on the IGC provides a visual
display of operational or sequential problems when the
power supply is uninterrupted. When a break in power
occurs, the IGC will be reset, resulting in a loss of fault
history, and the indoor (evaporator) fan ON/OFF times
will be reset. The LED error code can be observed
through the viewport. During servicing, refer to the label
on the control box cover or Table 13 for an explanation of
LED error code descriptions.
IMORTANT: Refer to the Troubleshooting Tables 17 and
18 for additional information.
If lockout occurs, unit may be reset by interrupting power
supply to unit for at least 5 seconds.
Table 13 – LED Error Code Description*
LED INDICATION
ON
OFF
2 Flashes
3 Flashes
4 Flashes
5 Flashes
6 Flashes
7 Flashes
8 Flashes
9 Flashes
LEGEND
LED - Light Emitting Diode
* A 3-second pause exists between LED error code flashes. If .
more than one error code exists, all applicable codes will be
displayed in numerical sequence.
Orifice Replacement
This unit uses orifice type LH32RFnnn (where nnn
indicates orifice reference size). When replacing unit
orifices, order the necessary parts through the Bryant
replacement parts division. See Table 14 for available
orifice sizes. See Tables 16 and 17 for orifice sizes for
Natural Gas and LP fuel usage at various elevations above
sea level. Never drill or plug orifices for operation.
Check that each replacement orifice is tight at its threads
into the manifold pipe and that orifice projection does not
exceed maximum value. See Fig. 50.
Table 14 – Orifice Sizes
ORIFICE
Bryant P/N
DRILL SIZE
#30 LH32RF129
1/8 LH32RF125
#31 LH32RF120
#32 LH32RF116
#33 LH32RF113
#34 LH32RF111
#35 LH32RF110
#36 LH32RF105
#37 LH32RF104
#38 LH32RF102
#39 LH32RF103
#40 LH32RF098
#41 LH32RF096
#42 LH32RF094
#43 LH32RF089
#44 LH32RF086
#45 LH32RF082
#46 LH32RF080
#47 LH32RF079
#48 LH32RF076
#49 LH32RF073
#50 LH32RF070
#51 LH32RF067
#52 LH32RF065
#53 LH32RF060
#54 LH32RF055
#55 LH32RF052
#56 LH32RF047
#57 LH32RF043
#58 LH32RF042
42
ERROR CODE DESCRIPTION
Normal Operation
Hardware Failure
Limit Switch Fault
Flame Sense Fault
4 Consecutive Limit Switch Faults
Ignition Lockout Fault
Induced-Draft Motor Fault
Rollout Switch Fault
Internal Control Fault
Software Lockout
DRILL DIA. (in.)
0.1285
0.1250
0.1200
0.1160
0.1130
0.1110
0.1100
0.1065
0.1040
0.1015
0.0995
0.0980
0.0960
0.0935
0.0890
0.0860
0.0820
0.0810
0.0785
0.0760
0.0730
0.0700
0.0670
0.0635
0.0595
0.0550
0.0520
0.0465
0.0430
0.0420