Cleaver-Brooks CB780 - Page 53

750-166 2-13
TABLE 4—FAULT MESSAGE AND RECOMMENDED TROUBLESHOOTING (Continued).
(Continued)
Fault Code System Failure Recommended Troubleshooting
Fault 33
*Preignition ILK*
Preignition Interlock fault. 1. Check wiring; correct any errors.
2. Inspect the Preignition Interlock switches and
assure proper funcitoning.
3. Check fuel valve operation. Valve must close
within five seconds.
4. Reset and sequence the CB 780/CB 784. During
Standby or Prepurge, measure the voltage
between terminal 20 and G (ground). 120 Vac
should be present. If not, the Preignition
Interlock switches may be defective and need
replacement.
5. If the fault persists, replace the relay module.
Fault 35
*Call Service*
Safety relay was off when it
should be on or fuse has blown.
1. Reset and sequence the CB 780/CB 784.
2. If fault persists, replace the relay module.
Fault 36
*Call Service*
Main valve terminal was off
when it should be on.
1. Reset and sequence the CB 780/CB 784.
2. If fault persists, replace the relay module.
Fault 37
*Call Service*
Pilot (ignition) valve terminal
was off when it should be on.
1. Reset and sequence the CB 780/CB 784.
2. If fault persists, replace the relay module.
Fault 38
*Call Service*
Ignition terminal was off when it
should be on.
1. Reset and sequence the CB 780/CB 784.
2. If fault persists, replace the relay module.
Fault 39
*Call Service*
V2S valve terminal was off
when it should be on.
1. Reset and sequence the CB 780/CB 784.
2. If fault persists, replace the relay module.
Fault 40
*Call Service*
Safety relay was on when it
should be off.
1. Reset and sequence the CB 780/CB 784.
2. If fault persists, replace the relay module.
Fault 41
*Main Valve On*
Main valve terminal was on
when it should be off.
1. Warning! Remove system power; turn off fuel
supply.
2. Check wiring to terminal 9; correct any errors.
3. Inspect the Main Fuel Valve(s) and connections.
Assure that switches are functioning correctly
and are not jumpered or welded.
4. Reset and sequence the CB 780/CB 784.
5. If the fault persists, replace the relay module.
Fault 42
*Pilot Valve On*
Pilot (ignition) valve terminal
was on when it should be off.
1. Warning! Remove system power; turn off fuel
supply.
2. Check wiring to terminal 8; correct any errors.
3. Inspect the Pilot Fuel Valve(s) and connections.
Assure that switch is functioning correctly and is
not jumpered or welded.
4. Reset and sequence the CB 780/CB 784.
5. If the fault persists, replace the relay module.
Fault 43
*Ignition On*
Ignition terminal was on when it
should be off.
1. Warning! Remove system power; turn off fuel
supply.
2. Check wiring to terminal 10; correct any errors.
3. Inspect the Ignition terminal and connections.
Assure that switch is functioning correctly and is
not jumpered or welded.
4. Reset and sequence the CB 780/CB 784.
5. If the fault persists, replace the relay module.