Manual for S7800A1142

Manual for S7800A1142

Brand: Honeywell

Category: Thermostat

Document Type: Manual

Language: EN

Available Languages: EN , ES

Uploaded: Nov. 21, 2025, 7:23 p.m.

Warranty Information

Refer to the product warranty for specific details.

The S7800A1142 Keyboard Display Module (KDM) provides current system status, first-out annunciation, and system diagnosis. It offers local or remote annunciation of operation and fault information, remote reset, report generation, burner control data, and diagnostic information. The KDM is part of the 7800 SERIES of microprocessor-based burner controls. It allows programming of the Valve Proving feature, naming of Expanded Annunciator terminals, displaying "Call Service" messages, and enabling ModBus Communication. Programming can be done with the KDM mounted on a 7800 SERIES Relay Module or with a 13 Vdc power source. A clone function allows creating multiple Business Cards from an original display.

Troubleshooting and error codes

Fault Code System Failure Recommended Troubleshooting
Fault 1
*No Purge Card*		 No card is plugged into the purge card slot. 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.
Fault 2
*AC Frequen/Noise		 Excess noise or device running on slow ac.
Ac line dropout detected.
Device running on fast ac.		 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.
Fault 3
*AC Line Dropout
Fault 4
*AC Frequency*
Fault 5
*Low Line Voltage*		 Low ac line detected. 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.
Fault 6
*Purge Card Error*		 Purge card timing changed since card was initially read. 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.
Fault 7
*Flame Amplifier*		 Flame sensed when flame not present. 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.
Fault 8
*Flame Amp/Shutr*		 Flame sensed when no signal expected during shutter-check or Ampli-Check™™ versions. 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.
Fault 9
*Flame Detected*		 Flame sensed when no flame is expected during STANDBY. 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.
Fault 10
*Pre-Ignition ILK*		 Pre-Ignition Interlock fault during STANDBY 1. Check wiring and correct any errors.
2. Check Pre-Ignition Interlock switches to assure proper functioning.
3. Check fuel valve operation.
4. Reset and sequence the relay module; monitor the Pre-Ignition Interlock status.
5. If the code persists, replace the relay module.
Privacy Policy