Honeywell 7800 Series Product Data page 15

4. State 4: In the fourth state, both lines are blanked for
one-half second, then the display sequences to the first
state.
Fault Code
Fault 1 No card is plugged into the
*No Purge Card* purge card slot.
Fault 2 Excess noise or device running
*AC Frequen/Noise on slow ac.
Fault 3 Ac line dropout detected.
*AC Line Dropout
Fault 4 Device running on fast ac.
*AC Frequency*
Fault 5 Low ac line detected.
*Low Line Voltage*
Fault 6 Purge card timing changed
*Purge Card Error* since card was initially read.
Fault 7 Flame sensed when flame not
*Flame Amplifier* present.
Fault 8 Flame sensed when no signal
*Flame Amp/Shutr* expected during shutter-check
or Ampli-Check™ versions.
Fault 9 Flame sensed when no flame is
*Flame Detected* expected during STANDBY.
Fault 10 Preignition Interlock fault during
*Preignition ILK* STANDBY
Table 7. Hold and Fault Message Summary.
System Failure
15
7800 SERIES S7800A KEYBOARD DISPLAY MODULE
NOTE: For further explanation of Lockout Messages, Trou-
bleshooting and Checkout, refer to form 65-0229.
Recommended Troubleshooting
1. Make sure the purge card is seated properly.
2. Inspect the purge card and connector on the relay module for
damage or contaminants.
3. Reset and sequence the relay module.
4. If the fault code reappears, replace the purge card.
5. Reset and sequence the relay module.
6. If the fault persists, replace the relay module.
1. Check the relay module and display module connections.
2. Reset and sequence the relay module.
3. Check the relay module power supply and make sure that both
frequency and voltage meed the specifications.
4. Check the backup power supply, as appropriate.
1. Make sure the purge card is seated properly.
2. Inspect the purge card and connector on the relay module for
damage or contaminants.
3. Reset and sequence the relay module.
4. If the fault code reappears, replace the purge card.
5. Reset and sequence the relay module.
6. If the fault persists, replace the relay module.
1. Check wiring and correct any errors. Make sure that the flame
sensor wires are in separate conduits. Check for noise
coupling into the flame detector leadwires.
2. Make sure that flame detector and flame amplifier are
compatible.
3. Remove the flame amplifier and inspect connections. Reset
the flame amplifier.
4. Reset and sequence the relay module.
5. If the code reappears, replace the amplifier.
6. If the fault persists, replace the flame detector.
7. If the fault persists, replace the relay module.
1. Check that flame is not present in the combustion chamber;
correct any errors.
2. Check wiring and correct any errors. Make sure that flame
sensor wires are in separate conduits. Check for noise
coupling into flame detector leadwires.
3. Remove the flame amplifier and inspect its connections. Reset
the amplifier.
4. Reset and sequence the relay module.
5. If the code reappears, replace the amplifier and/or the flame
detector.
6. If the fault persists, replace the flame detector.
7. If the fault persists, replace the relay module.
1. Check wiring and correct any errors.
2. Check Preignition Interlock switches to assure proper
functioning.
3. Check fuel valve operation.
4. Reset and sequence the relay module; monitor the Preignition
Interlock status.
5. If the code persists, replace the relay module.
65-0090—4