A.O. Smith Error Code LOC: Controls Locked
Warning: The water heater controls are locked, preventing normal operation. This usually requires a service call to unlock and diagnose the cause.
How to Fix A.O. Smith Code LOC
- Step 1: Check the owner's manual for specific instructions on how to unlock the control panel. Some models have a button combination or a sequence of presses to unlock.
- Step 2: Try cycling power to the water heater by turning off the breaker for a few minutes, then turning it back on. This may reset the control board and clear the lock.
- Step 3: If the above steps don't work, contact a qualified HVAC technician to diagnose and unlock the control panel. Do not attempt to disassemble or repair the unit yourself.
How to Reset A.O. Smith Code LOC
- Turn off the unit using the power button on the front panel.
- Turn off the gas supply valve.
- Turn off the circuit breaker supplying power to the unit. Wait 30 seconds.
- Restore power at the breaker, then open the gas valve.
- Turn the unit back on. If the error returns, the underlying issue needs repair.
What does LOC mean?
The 'LOC' error code on your A.O. Smith water heater indicates that the control panel has been locked. This feature is designed to prevent unauthorized changes to the water heater's settings. When locked, the unit will typically not respond to button presses or temperature adjustments, effectively disabling its normal functionality.
This lockout can occur for several reasons, including accidental activation of the lock feature, a software glitch, or as a safety measure triggered by an underlying issue within the water heater. Because the unit is locked, you won't be able to adjust the temperature or access diagnostic information until it's unlocked. This usually requires specific knowledge of A.O. Smith control systems.
Affected Models
Replacement Parts
| Part | OEM Number | Est. Cost |
|---|---|---|
| Control Board | — | — |
| Keypad/Button Assembly | — | — |
| Wiring Harness | — | — |
Related Codes on Same Models
| Code | Description | Severity |
|---|---|---|
| E1 | Thermistor Failure | Warning |
| E2 | Dry Fire Protection | Warning |
| E3 | Sensor Fault | Warning |
| E4 | High Temperature Cutoff | Critical |
| E5 | Communication Error | Warning |
| E06 | Flammable Vapor Detection | Critical |
| ECO | Emergency Cutoff | Critical |
| UPR | Upper Element Fault | Warning |
| LWR | Lower Element Fault | Warning |