Specifications

24 IM 685-2
BLINKING FAULT CODES...
Fault Code System Failure
Code 1-1
*Low AC Line
Voltage*
Low AC Line detected.
a. Check the relay module and display module connections.
b. Reset and sequence the Relay Module.
c. Check the 7800 power supply and make sure that frequency and voltage meet specifications.
d. Check the backup power supply, as appropriate.
Code 1-2
*AC Quality
Problem*
Excessive noise or
device running on slow,
fast, or AC line dropout
detected.
Code 2-1
*Unexpected
Flame Signal*
Flame sensed when no
flame is expected during
STANDBY or PURGE.
a. Check that flame is not present in the combustion chamber; correct any errors.
b. Make sure that the flame amplifier and flame detector are compatible.
c. Check the wiring and correct any errors.
d. Remove the flame amplifier and inspect its connections. Reseat the amplifier.
e. Reset and sequence the relay module.
f. If the code reappears, replace the flame amplifier and/or the flame detector.
g. If the fault persists, replace the relay module.
Code 2-2
*Flame Signal
Absent*
No-flame time present
at the end of the PIlot
Flame Establishing
Period; lost during the
Main Flame Establishing
Period or during RUN.
a. Measure the flame signal. If one exists, verify that it meets specifications.
b. Make sure that the flame amplifier and flame detector are compatible.
c. Inspect the main fuel valve(s) and valve connection(s).
d. Verify that the fuel pressure is sufficient to supply fuel to the combustion
chamber. Inspect the connections to the fuel pressure switches. Make sure they are functioning properly.
e. Inspect the Airflow Switch and make sure that it is functioning properly.
f. Check the flame detector sighting position; reset and recycle. Measure the flame signal strength. Verify
that it meets specifications. If not, refer to the flame detector and/or flame amplifier checkout procedures
in the installation instructions.
g. Replace the flame amplifier and/or the flame detector, if necessary.
h. If the fault persists, replace the relay module.
Code 2-3
*Flame Signal
Overrange*
Flame signal value is
too high to be valid.
a. Make sure the flame detector and flame amplifier are compatible.
b. Remove the flame amplifier and inspect its connections. Reset the flame amplifier.
c. Reset and sequence the relay module.
d. Check the flame detector sighting position; reset and recycle. Measure flame strength. Verify that it meets
specifications. If not, refer to the flame detector and/or flame amplifier checkout procedures in the installa-
tion instructions.
e. If the code reappears, replace the flame amplifier and/or the flame detector.
f. If the fault persists, replace the relay module.
Code 3-1
*Running/
Interlock Switch
Problem*
Running or Lockout
Interlock fault during
Prepurge.
a. Check wiring; correct any errors.
b. Inspect the fan; make sure there is no air intake blockage and that it is supplying air.
c. Make sure the Lockout Interlock switches are functioning properly and the contacts are free from contam-
inants.
d. Reset and sequence the relay module to Prepurge (place the TEST/RUN Switch in the TEST position, if
available). Measure the voltage between terminal 7 and G (ground); 120 Vac should be present. Switch
TEST/RUN back to RUN.
e. If steps 1 through 4 are correct and the fault persists, replace the relay module.
Code 3-2
*Running/
Interlock On
During
Standby*
Lockout Interlock
powered at improper
point in sequence or On
in Standby.
a. Check wiring to make sure that the Lockout Interlocks are connected properly between terminals 6 and 7.
Correct any errors.
b. Reset and sequence the relay module.
c. If the fault persists, measure the voltage between terminal 6 and G (ground), then between terminal 7 and
G. If there is 120 Vac at terminal 6 when the controller is off, the controller switch may be bad or is jum-
pered.
d. If steps 1 through 3 are correct and there is 120 Vac at terminal 7 when the controller is closed and the
fault persists, check for a welded or jumpered Running Interlock or Airflow Switch. Correct any errors.
e. If steps 1 through 4 are correct and the fault persists, replace the relay module.
Code 3-3
*VPS in
Improper State*
VPS (Valve Proving
Switch) in wrong state
during VPS Test.
a. Check wiring, making sure upstream valve is connected to terminal 9 and downstream valve is connected
to terminal 17.
b. Conduct Valve Seat leakage test using a manometer.
c. Reset and sequence the relay module; if fault repeats, test VPS (connected to terminal 16) is functioning
properly; replace if necessary.
d. Reset and sequence the relay module.
e. If fault persists, replace the relay module.
Table 6. Fault codes