Bosch BGH96M060B3A Installation, Operation And Maintenance Manual page 51

Installation, Operation & Maintenance Manual
Symptoms of
Associated
Abnormal Fault Description(s)
LED
Operation
RED
— Lockout due to
failed ignition
Furnace fails
7 FLASH
— Lockout due to
to operate
8 FLASH
too many flame
dropouts
Furnace fails — Incorrect line
9 FLASH
to operate
voltage polarity
— Gas valve fault
Furnace fails
10 FLASH
to operate
code
Furnace fails
— Control failure
SOLID
to operate
AMBER
Normal — Call for heat
1 FLASH
Operation
active
— Y thermostat
Normal
4 FLASH demand without
Operation
G
Abnormal
— Low flame sense
furnace
RAPID
current
operation
GREEN
Abnormal
— Control in Factory
furnace
RAPID
Test mode
operation
Normal
— Standby mode
1 FLASH
Operation
Table 26
Troubleshooting Chart
Bosch Thermotechnology Corp. | 04.2019
Possible Reason
— The gas valve switched off
— Iginitor failure
— Orifices are blocked/clogged
— Flame sensor dirty or broken
— Furnace improperly grounded
— Manifold gas pressure does not
meet the requirement
— Inlet gas pressure does not meet
the requirement
— Wrong L1/L2 connection
— Valve receives voltage from a
short
— Control module failure
— Control module failure
―
— G wire not connected properly
— Thermostat failure
— Flame sensor is coated/oxidized
— Flame sensor is incorrectly
positioned in the burner flame.
— Lazy burner flame due to
improper gas pressure or
combustion air.
— Control board error
— Control module failure
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Bosch 96% AFUE Gas Furnace | 51
Corrective Action
1. Turn the gas valve switch to "On"
2. Replace ignitor
3. Remove the blockage
4. Clean with steel wool.or replace the
fl ame sensor.
5. Properly ground the wire
6. Adjust the gas valve. Replace the gas
valve.
7. Check incoming gas supply quality.
Adjust the inlet gas pressure to meet
requirement on nameplate.
1. Correct the wire connection
1. Correct the wire connection
2. Replace control module
1. Replace control module
―
1. Correct the wire connection
2. Replace thermostat
1. Clean/sand fl ame sensor with steel
wool.
2. Inspect for proper sensor alignment.
3. Compare current gas pressure to
rating plate info. Adjust as needed.
1. Restart furnace
2. Replace control module
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Cautions And Notes
— Turn power OFF prior to repair.
— Turn power OFF prior to repair.
— Turn power OFF prior to repair.
— Turn power OFF prior to repair.
―
―
— Turn power OFF prior to repair.
— Clean flame sensor with steel
wool.
— See Section 8 for piping
details.
— See rating plate for proper gas
pressure.
— Turn power OFF prior to repair.
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Data subject to change