Submittal Sheet

7800 SERIES S7800A2142 KEYBOARD DISPLAY MODULE
25 32-00110—05
Fault 62 MV2 Off (Terminal 17);
should be ON.
1. Check wiring and correct any errors.
2. Reset and sequence the control.
3. If fault persists, replace relay module (Before installing the
new relay module, verify current draw of terminal 17).
Fault 63 MV1 ON (Terminal 9); should
be OFF.
1. Check wiring and correct any errors.
2. Reset and sequence the control.
3. If fault persists, replace relay module (Before installing the
new relay module, verify current draw of terminal 9).
Fault 64 MV2 ON (Terminal 17);
should be OFF.
1. Check wiring and correct any errors.
2. Reset and sequence the control.
3. If fault persists, replace relay module (Before installing the
new relay module, verify current draw of terminal 17).
Fault 65
*VPS Off*
Valve Proving Switch
(Terminal 16) OFF; should be
ON.
(VPS High Test)
1. Check wiring and correct any errors.
2. Check MV2 for leaking valve seat.
3. Reset and sequence control.
Fault 66
*VPS On*
Valve Proving Switch
(Terminal 16) ON; should be
OFF.
(VPS Low Test)
1. Check wiring and correct any errors.
2. Check MV1 for leaking valve seat.
3. Reset and sequence control.
Fault 67
*AC Phase*
L1 and L2
miswired/exchanged
(EC/RM7850 only).
1. Check L1 and L2 for proper line phasing.
Fault 68
*Pre-Ignition ILK*
Pre-Ignition Interlock fault. 1. Check wiring and correct any errors.
2. Inspect the Pre-Ignition Interlock switches and make sure
they work properly.
3.
Check fuel valve operation. Valve must close within five
seconds.
4. Reset and sequence the relay module.
5.
During STANDBY or PREPURGE, measure the voltage between
terminal 17 and L2(N). Supply voltage should be present. If
not, the Pre-Ignition Interlock switches are defective and need
replacing.
6. If the fault persists, replace the relay module.
Faults 69 - 70
*Call Service*
Unused faults. —
Fault 71
*Dynamic LFS*
Low Fire Switch closed, High
Fire Switch must be open
(EC/RM 7850 only).
1. Check firing rate position switches (usually in Modutrol®
Motor) for proper operation.
2. Check wiring and correct any errors.
3. Reset and sequence the relay module.
4. If the fault persists, replace the relay module.
Fault 71
*Limits Complete*
Limit Input (terminal 7) is off
when it should be on
(RM7888 only).
1. Check limits to make sure they are satisfied after resetting.
2. Check electrical connections to terminal 7 of wiring sub-
base.
3. Reset relay module.
4. If the fault persists, replace the relay module.
Fault 72
*Dynamic HFS*
High Fire Switch closed; Low
Fire Switch must be open
(EC/RM7850 only).
1. Check firing rate position switches (usually in Modutrol®
Motor) for proper operation.
2. Check wiring and correct any errors.
3. Reset and sequence the relay module.
4. If the fault persists, replace the relay module.
Fault 72
*Spec.Func.2*
Special Function 2 Input
(terminal 17) is off when it
should be on (Device
specific).
1. Check operation of Special Function 2 of PLC.
2. Check electrical connection to terminal 17 of wiring sub-
base and confirm presence of supply power when Special
Function 2 is activated.
3. Reset relay module.
4. If the fault persists, replace the relay module.
Table 5. Fault Message Summary. (Continued)
Fault Code System Failure Recommended Troubleshooting