2-10 750-166
TABLE 4—FAULT MESSAGE AND RECOMMENDED TROUBLESHOOTING (Continued).
Fault Code System Failure Recommended Troubleshooting
Fault 14
*High Fire Sw.*
High fire interlock switch failure
to close during prepurge.
1. Check wiring; correct any errors.
2. Reset and sequence the CB 780/CB 784.
3. Use either the manual motor potentiometer to
drive the motor to the High Fire position or use
the Run/Test switch option (if available)
sequence to Prepurge Drive to High Fire and
place in the TEST position. Adjust the High Fire
switch while in this state to assure that it is
closing properly.
4. Measure the voltage between terminal 18 and
G (ground) while in the Prepurge Drive to High
Fire state. 120 Vac should be present. If not, the
switch adjustment is incorrect and/or the switch
is defective and should be replaced.
5. Reset and sequence the CB 780/CB 784. If
120 Vac was present between the High Fire
switch and terminal 18, and the fault still persists,
replace the relay module.
Fault 15
*Flame Detected*
Flame sensed when shutter open
and no flame is expected.
1. Check that flame is not present in the combustion
chamber; correct any errors.
2. Assure that the flame amplifier and flame
detector are compatible.
3. Check wiring and correct any errors.
4. Remove the flame amplifier and inspect its
connectors. Reseat the flame amplifier.
5. Reset and sequence the CB 780/CB 784.
6. If the code reappears, replace the flame amplifier
and/or the flame detector.
7. If fault persists, replace the relay module.
Fault 16
*Flame-Out Timer*
Integrated no-flame time
exceeded the limit during Pilot
Flame Establishing Period.
1. Measure the flame signal. If one exists, does it
meet specifications? Make appropriate burner
adjustments.
2. Assure that the flame amplifier and the flame
detector are compatible.
3. Replace the flame amplifier and/or the flame
detector, if necessary.
4. If the fault persists, replace the relay module.
Fault 17
*Main Flame Fail*
Main flame failure during Run
after flame was established and
on for at least 10 seconds.
1. Inspect the main fuel valve(s) and its
connection(s).
2. Verify that the fuel pressure is sufficient enough
to supply fuel to the combustion chamber.
Inspect the connections to the fuel pressure
switches. Assure tproper functioning.
3. Inspect the Airflow Switch and assure that it is
functioning properly.
4. Check the flame detector sighting position; reset
and cycle. Measure flame signal strength. Does it
meet specifications? If not, refer to the flame
detector and/or flame amplifier checkout
procedures in the installation instructions.
(Continued)
To Next Page
Loading...