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RM7897A,C 7800 SERIES RELAY MODULES
Fault Code System Failure
Code 1-1
Low AC Line
*Low AC Line
detected.
Voltage*
Code 1-2
Excessive noise
*AC Quality
or device
Problem*
running on slow,
fast, or AC line
dropout
detected.
Code 2-1
Flame sensed
*Unexpected
when no flame is
Flame
expected during
Signal*
STANDBY or
PURGE.
Code 2-2
No-flame time
*Flame
present at the
Signal
end of the PIlot
Absent*
Flame
Establishing
Period; lost
during the Main
Flame
Establishing
Period or during
RUN.
Code 2-3
Flame signal
*Flame
value is too high
Signal
to be valid.
Overrange*
Code 3-1
Running or
*Running/In
Lockout
terlock
Interlock fault
Switch
during Prepurge.
Problem*
Code 3-2
Lockout
*Running/In
Interlock
terlock On
powered at
During
improper point
Standby*
in sequence or
On in Standby.
Code 3-3
VPS (Valve
*VPS in
Proving Switch)
Improper
in wrong state
State*
during VPS Test.
32-00158—03
Table 8. Blinking Fault Codes and Recommended Troubleshooting.
1. Check the relay module and display module connections.
2. Reset and sequence the Relay Module.
3. Check the 7800 power supply and make sure that frequency and voltage meet
specifications.
4. Check the backup power supply, as appropriate.
1. Check that flame is not present in the combustion chamber; correct any errors.
2. Make sure that the flame amplifier and flame detector are compatible.
3. Check the wiring and correct any errors.
4. Remove the flame amplifier and inspect its connections. Reseat the amplifier.
5. Reset and sequence the relay module.
6. If the code reappears, replace the flame amplifier and/or the flame detector.
7. If the fault persists, replace the relay module.
1. Measure the flame signal. If one exists, verify that it meets specifications.
2. Make sure that the flame amplifier and flame detector are compatible.
3. Inspect the main fuel valve(s) and valve connection(s).
4. 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.
5. Inspect the Airflow Switch and make sure that it is functioning properly.
6. 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.
7. Replace the flame amplifier and/or the flame detector, if necessary.
8. If the fault persists, replace the relay module.
1. Make sure the flame detector and flame amplifier are compatible.
2. Remove the flame amplifier and inspect its connections. Reset the flame amplifier.
3. Reset and sequence the relay module.
4. 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 installation instructions.
5. If the code reappears, replace the flame amplifier and/or the flame detector.
6. If the fault persists, replace the relay module.
1. Check wiring; correct any errors.
2. Inspect the fan; make sure there is no air intake blockage and that it is supplying air.
3. Make sure the Lockout Interlock switches are functioning properly and the contacts are
free from contaminants.
4. 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.
5. If steps 1 through 4 are correct and the fault persists, replace the relay module.
1. Check wiring to make sure that the Lockout Interlocks are connected properly between
terminals 6 and 7. Correct any errors.
2. Reset and sequence the relay module.
3. 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 jumpered.
4. 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.
5. If steps 1 through 4 are correct and the fault persists, replace the relay module.
1. Check wiring, making sure upstream valve is connected to terminal 9 and downstream
valve is connected to terminal 17.
2. Conduct Valve Seat leakage test using a manometer.
3. Reset and sequence the relay module; if fault repeats, test VPS (connected to terminal 16)
is functioning properly; replace if necessary.
4. Reset and sequence the relay module.
5. If fault persists, replace the relay module.
Recommended Troubleshooting
16
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