A.O. Smith 3400 - Manual (Page 62)

62
CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF
LOCKOUT CODES
NOTE
94 Header sensor fault 1. Check wiring and correct any possible errors.
2. Replace the header sensor.
3. If previous steps are correct and fault persists,
replace the module.
H
95 Stack sensor fault 1. Check wiring and correct any possible errors.
2. Replace the stack sensor.
3. If previous steps are correct and fault persists,
replace the module.
H
96 Outdoor sensor fault 1. Check wiring and correct any possible errors.
2. Replace the outdoor sensor.
3. If previous steps are correct and fault persists,
replace the module.
H
97 Internal Fault: A2D mismatch. Internal Fault.
1. Reset Module.
2. If fault repeats, replace module.
L
98 Internal Fault: Exceeded VSNSR voltage L
99 Internal Fault: Exceeded 28V voltage tolerance L
100 Pressure Sensor Fault 1. Verify the Pressure Sensor is a 4-20 ma source.
2. Check wiring and correct any possible errors.
3. Test Pressure Sensor for correct operation.
4. Replace the Pressure sensor.
5. If previous steps are correct and fault persists,
replace the module.
H
101-104 RESERVED
Flame Operation Faults
105 Flame detected out of sequence 1. Check that flame is not present in the combustion
chamber. Correct any errors.
2. Make sure that the flame detector is wired to the
correct terminal.
3. Make sure the F & G wires are protected from
stray noise pickup.
4. Reset and sequence the module, if code
reappears, replace the flame detector.
5. Reset and sequence the module, if code
reappears, replace the module.
H or L
106 Flame lost in MFEP 1. Check pilot valve (Main Valve for DSI) wiring and
operation - correct any errors.
2. Check the fuel supply.
3. Check fuel pressure and repeat turndown tests.
4. Check ignition transformer electrode, flame
detector, flame detector siting or flame sensor
position.
5. If steps 1 through 4 are correct and the fault
persists, replace the module.
L
107 Flame lost early in run L
108 Flame lost in run L
109 Ignition failed L
110 Ignition failure occurred Hold time of recycle and hold option. Will not be a
lockout fault. Hold Only.
H
111 Flame current lower than WEAK threshold Internal hardware test. Not a lockout, H
112 Pilot test flame timeout Interrupted Pilot or DSI application and flame lost
when system in “test” mode.
1. Reset the module to restart.
L
113 Flame circuit timeout Flame sensed during Initiate or off cycle, hold 240
seconds, if present after 240 seconds, lockout.
L
114-116 RESERVED
117 Condensate Fault 1. Check the condensate trap at the back of the
boiler for any blockage.
2. Check the exhaust vent piping for any blockage.
L
118-121 RESERVED
Rate Proving Faults