A.O. Smith 3400 - Manual (Page 64)

64
CODE DESCRIPTION RECOMMENDED TROUBLESHOOTING OF
LOCKOUT CODES
NOTE
149 Flame detected OEM Specific
1. Holds if flame detected during Safe Start check
up to Flame Establishing period.
H or L
150 Flame not detected OEM Specific
1. Sequence returns to standby and restarts
sequence at the beginning of Purge after the HF
switch opens. If flame detected during Safe Start
check up to Flame Establishing period.
H
151 High fire switch ON OEM Specific
1. Check wiring and correct any potential wiring
errors.
2. Check High Fire Switch to assure proper function
(not welded or jumpered).
3. Manually drive the motor to the High Fire position
and adjust the HF switch while in this position
and verify voltage through the switch to the HFS
input with a voltmeter.
4. If steps 1-3 are correct and the fault persists,
replace the module.
H or L
152 Combustion pressure ON OEM Specific
1. Check wiring and correct any errors.
2. Inspect the Combustion Pressure Switch to make
sure it is working correctly.
3. Reset and sequence the relay module.
4. During STANDBY and PREPURGE, measure
the voltage between Terminal J6-5 and L2 (N).
Supply voltage should be present. If not, the
lockout switch is defective and needs replacing.
5. If the fault persists, replace the relay module.
H or L
153 Combustion pressure Off H or L
154 Purge Fan switch On OEM Specific
1. Purge fan switch is on when it should be off.
H or L
155 Purge Fan switch Off H
156 Combustion pressure and Flame ON OEM Specific
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.
H or L
157 Combustion pressure and Flame OFF L
158 Main valve ON OEM Specific
1. Check Main Valve terminal wiring and correct any
errors.
2. Reset and sequence the module. If fault persist,
replace the module.
L
159 Main valve OFF L
160 Ignition ON OEM Specific
1. Check Ignition terminal wiring and correct any
errors.
2. Reset and sequence the module. If fault persist,
replace the module.
L
161 Ignition OFF L
162 Pilot valve ON OEM Specific
1. Check Pilot Valve terminal wiring and correct any
errors.
2. Reset and sequence the module. If fault persist,
replace the module.
L
163 Pilot valve OFF L