A.O. Smith 3400 - Manual (Page 61)

61
CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF
LOCKOUT CODES
NOTE
67 ILK OFF 1. Check wiring and correct any possible shorts.
2. Check Interlock (ILK) switches to assure proper
function.
3. Verify voltage through the interlock string to the
interlock input with a voltmeter.
4. If steps 1-3 are correct and the fault persists,
replace the module.
H or L
68 ILK ON H or L
69 Pilot test hold 1. Verify Run/Test is changed to Run.
2. Reset Module.
3. If fault repeats, replace module.
H
70 Wait for leakage test completion 1. Internal Fault. Reset Module.
2. If fault repeats, replace module.
H
71 - 77 RESERVED
78 Demand Lost in Run 1. Check wiring and correct any possible errors.
2. If previous steps are correct and fault persists,
replace the module.
H
79 Outlet high limit 1. Check wiring and correct any possible errors.
2. Replace the Outlet high limit.
3. If previous steps are correct and fault persists,
replace the module.
H or L
80 DHW high limit 1. Check wiring and correct any possible errors.
2. Replace the DHW high limit.
3. If previous steps are correct and fault persists,
replace the module.
H or L
81 Delta T limit 1. Check Inlet and Outlet sensors and pump circuits
for proper operation.
2. Recheck the Delta T Limit to confirm proper
setting.
3. If previous steps are correct and fault persists,
replace the module.
H or L
82 Stack limit 1. Check wiring and correct any possible errors.
2. Replace the Stack high limit.
3. If previous steps are correct and fault persists,
replace the module.
H or L
83 Delta T exchanger/outlet limit Not Applicable. H or L
84 Delta T inlet/exchanger limit Not Applicable. H or L
85 Inlet/outlet inversion limit Not Applicable. H or L
86 Exchanger/outlet inversion limit Not Applicable. H or L
87 Inlet/exchanger inversion limit Not Applicable. H or L
88 Outlet T-rise limit Check for adequate flow. H or L
89 Exchanger T-rise limit Not Applicable. H or L
90 Heat exchanger high limit Not Applicable. H or L
Sensor Faults
91 Inlet sensor fault 1. Check wiring and correct any possible errors.
2. Replace the Inlet sensor.
3. If previous steps are correct and fault persists,
replace the module.
H
92 Outlet sensor fault 1. Check wiring and correct any possible errors.
2. Replace the Outlet sensor.
3. If previous steps are correct and fault persists,
replace the module.
H
93 DHW sensor fault 1. Check wiring and correct any possible errors.
2. Replace the DHW sensor.
3. If previous steps are correct and fault persists,
replace the module.
H