U.S. Boiler Company B series 2 Installation, Operating And Service Instructions - page 21
1
Table : Green LED Flame Codes
Green LED
Flash
Code
a
Indicates
Next System Action
Recommended Service Action
OFF
No “Call for Heat”
N/A
None
Flash Fast
Power up - internal check
N/A
None
Heartbeat
Normal startup - ignition sequence
started (including prepurge)
N/A
None
4 Seconds ON
then “x” flashes
Device in run mode.
“x” = flame current to the nearest µA.
N/A
None
2
5 minute Retry Delay
- Pilot flame not detected during trial for
ignition
Initiate new trial for ignition after retry
delay completed.
If system fails to light on next trial for ignition
check gas supply, pilot burner, spark and
flame sense wiring, flame rod contamination or
out of position, burner ground connection.
3
Recycle
- Flame failed during run
Initiate new trial for ignition. Flash code
will remain through the ignition trial until
flame is proved.
If system fails to light on next trial for ignition,
check gas supply, pilot burner, flame sense
wiring, contamination of flame rod, burner
ground connection.
4
Flame sensed out of sequence
If situation self corrects within 10
seconds, control returns to normal
sequence. If flame out of sequence
remains longer than 10 seconds, control
will resume normal operation 1 hour
after error is corrected.
Check for pilot flame. Replace gas valve if pi-
lot flame present. If no pilot flame, cycle “Call
for Heat.” If error repeats, replace control.
6
Control Internal Error
Control remains in wait mode. When
the fault corrects, control resumes
normal operation.
Cycle “Call for Heat”. If error repeats, replace
control.
7
Flame rod shorted to ground
Control remains in wait mode. When
the fault corrects, control resumes
normal operation.
Check flame sense lead wire for damage or
shorting. Check that flame rod is in proper
position. Check flame rod ceramic for cracks,
damage or tracking.
8
Low secondary voltage supply- (below
15.5 Vac)
Control remains in wait mode. When
the fault corrects, control resumes
normal operation.
Check transformer and AC line for proper input
voltage to the control. Check with full system
load on the transformer.
a
Flash Code Descriptions:
- Flash Fast: rapid blinking
- Heartbeat: Constant ½ second bright, ½ second dim cycles.
- 4 second solid on pulse followed by “x” 1 second flashes indicates flame current to the nearest µA. This is only available in run mode.
- A single flash code number signifies that the LED flashes X times at 2Hz, remains off for two seconds, and then repeats the sequence.
d. The minimum steady pilot flame signal
must be 1 μAmp (microampere) DC (direct
current).
e. For reliable operation the flame current
should be 2 μAmp or greater.
f. To ensure adequate flame current:
i. Turn off boiler power at circuit breaker
or fuse box
ii. Clean the flame rod with emery cloth if
required
iii. Make sure electrical connections are
clean and tight, and wiring not damaged,
repair/replace as needed
iv. Check for igniter/sensor cracked ceramic
insulator, replace if needed
v. Check the pilot flame. It must be blue,
steady and envelop the flame sensing rod
3/8” to ½”.
vi. If needed, adjust pilot flame by turning
the gas valve pilot adjustment screw
clockwise to decrease or
counterclockwise to increase pilot flame.
Always reinstall pilot adjustment screw
cover and tighten securely upon
completion to assure proper gas valve
operation.
g. Reconnect Mv lead wire to the module upon
satisfactory completion of pilot flame
current measurement.
h. Check the pilot burner operation/ignition
sequence during ignition cycle:
i. Restore boiler power at circuit breaker or
fuse box.
ii. Set thermostat to call for heat.
iii. Watch ignition sequence at burner.
iv. If spark does not stop after pilot lights,
replace ignition module.
v. If main burners do not light or if main
burners light but system locks out, check
the module ground wire and gas control
as described in Figure 28 “ honeywell
Electronic Ignition Troubleshooting
Guide”.