Troubleshooting Codes - A.O. Smith 100 Series Service Handbook

To support the recommended Troubleshooting, the R7910 has an Alert File. Review the Alert history for possible trends that may have
been occurring prior to the actual Lockout.
Note Column: H= Hold message; L=Lockout message; H or L= either Hold or Lockout depending on Parameter Configuration.
CODE
Safety Data Faults
1 Unconfigured safety data
2 Waiting for safety data verification
Internal Operation Errors
3 Internal fault: Hardware fault
4 Internal fault: Safety Relay key feedback error
5 Internal fault: Unstable power (DCDC) output
6 Internal fault: Invalid processor clock
7 Internal fault: Safety relay drive error
8 Internal fault: Zero crossing not detected
9 Internal fault: Flame bias out of range
10 Internal fault: Invalid Burner control state
11 Internal fault: Invalid Burner control state flag
12 Internal fault: Safety relay drive cap short
13 Internal fault: PII shorted to ILK
14 Internal fault: HFS shorted to LCI
15 Internal fault: Safety relay test failed due to
feedback ON
16 Internal fault: Safety relay test failed due to safety
relay OFF
17 Internal fault: Safety relay test failed due to safety
relay not OFF
18 Internal fault: Safety relay test failed due to
feedback not ON
19 Internal fault: Safety RAM write
20 Internal fault: Flame ripple and overflow
21 Internal fault: Flame number of sample mismatch
22 Internal fault: Flame bias out of range
23 Internal fault: Bias changed since heating cycle
starts
24 Internal fault: Spark voltage stuck low or high
25 Internal fault: Spark voltage changed too much
during flame sensing time
26 Internal fault: Static flame ripple
27 Internal fault: Flame rod shorted to ground
detected
28 Internal fault: A/D linearity test fails
29 Internal fault: Flame bias cannot be set in range
60

TROUBLESHOOTING CODES

TABLE 12. TROUBLESHOOTING CODES
DESCRIPTION
Servicing should only be performed by a Qualified Service Agent
RECOMMENDED TROUBLESHOOTING OF
LOCKOUT CODES
1. New Device, complete device configuration and
safety verification.
2. If fault repeats, replace module.
1. Device in Configuration mode and safety
parameters need verification and a device needs
reset to complete verification.
2. Configuration ended without verification, re enter
configuration, verify safety parameters and reset
device to complete verification.
3. If fault repeats, replace module.
Internal Fault.
1. Reset Module.
2. If fault repeats, replace module.
NOTE
L
L
H
H
H
H
H
H
H
L
L
H
H or L
H or L
L
L
L
L
L
H
H
H
H
H
H
H
H
H
H