AO Smith
AO Smith Water Softeners Error Codes
Complete list of fault codes and troubleshooting guides. Use the search below to find your specific error.
Advertisements
Err 01
Control panel displays “Err 01” and regeneration will not start automatically.
Turbine / Flow Sensor Failure
Err 02
Display shows “Err 02” and the unit will not advance through regeneration cycles.
Motor or Cam Position Fault
Err 03
Control displays “Err 03” and the softener is stuck in one regeneration position (e.g., brine draw or backwash).
Valve Position Switch / Encoder Error
Err 04
Display shows “Err 04” and the time or regeneration settings will not save or stay accurate.
Control Board Memory / Programming Fault
Err 05
Display shows “Err 05” and the unit will not initiate or complete brine draw.
Brine Valve / Injector Blockage
Err 06
Display shows “Err 06” and the unit reports a salt system problem or low salt even when salt is present.
Salt Level Sensor / Brine Well Sensor Fault
Err 07
Display shows “Err 07” and the unit indicates a high flow or leak condition even when no water is running.
False High-Flow / Leak Detection from Flow Sensor
Err 08
Display shows “Err 08” and the softener will not recognize when the brine tank is refilled or when regeneration completes.
Regeneration Completion / Sensor Feedback Error
Err 09
Display shows “Err 09” and the unit reports a power or low-voltage fault.
Low Voltage / Power Supply Error
Err 10
Display shows “Err 10” and the unit indicates an internal sensor or configuration error.
Internal Control Self-Test Failure
Lo Brine
Display shows “Lo Brine” or “Check Brine” and regeneration is ineffective.
Insufficient Brine Concentration
Lo Salt
Display shows “Lo Salt” or a salt icon, and an audible alarm may sound.
Low Salt Level Warning
No Flow
Display shows “No Flow” even when water is being used in the home, or unit never regenerates on demand.
Flow Meter Not Registering Usage
Service
Display shows “Service” or “Call for Service” without a numeric code, and softener may not regenerate.
General System Fault / Service Reminder
Symptom
Brine tank fills with water and may overflow.
Brine Tank Overfill
Symptom
Salt forms a hard crust (bridge) in the brine tank and the softener stops softening.
Salt Bridging
Symptom
Salt turns into a thick mush at the bottom of the brine tank and brine draw becomes unreliable.
Salt Mushing
Symptom
Softener appears to regenerate too frequently (daily or more) without obvious reason.
Excessive Regeneration Frequency
Symptom
Softener backwashes to drain but does not draw brine or refill properly.
Partial Regeneration Function
Symptom
Softener causes noticeable drop in water pressure throughout the home.
Flow Restriction Through Softener
Symptom
Softener causes water hammer or banging pipes when it changes cycles.
Rapid Valve Shifts / High Flow Rate Shock
Symptom
Softener does not regenerate at the programmed time (e.g., 2 AM) and appears to skip cycles.
Regeneration Not Initiating
Symptom
Softener drains continuously to the drain line, even when not regenerating.
Valve Not Sealing in Service Position
Symptom
Softener emits a constant humming noise even when not regenerating.
Transformer or Motor Hum
Symptom
Softener is stuck in regeneration and does not return to service; water may be hard or unavailable.
Valve Stuck Mid-Cycle
Symptom
Softener makes loud clicking, grinding, or knocking noises during regeneration.
Mechanical Drive Noise / Gear Damage
Symptom
Softener resin is found in household plumbing fixtures (small amber beads in aerators).
Resin Loss into Plumbing
Symptom
Softener uses no salt; salt level in the brine tank never drops.
No Brine Draw During Regeneration
Symptom
Softener uses too much salt; salt level drops very quickly and salt consumption is higher than expected.
Excessive Brine Refill / Over-Regeneration
Symptom
Softener will not power on; display is blank.
No Power to Control Head
Symptom
Softener will not start a manual regeneration when the button is pressed.
Manual Regeneration Control Failure
Symptom
Water has a salty taste after regeneration.
Incomplete Rinse / Excess Brine Carryover
Symptom
Water has an unusual odor (musty, rotten egg, or metallic) after installing or servicing the softener.
Odor Related to Softener or Plumbing
Symptom
Water is intermittently hard, especially just before scheduled regeneration.
Undersized System / Incorrect Capacity Programming
Symptom
Water remains hard even though the AO Smith water softener appears to run and regenerate normally.
Insufficient Softening Capacity / Resin Exhaustion
Symptom
Water softener is leaking from around the control valve head.
Control Valve Head Leak
Symptom
Water softener is leaking from the brine tank or around the brine well.
Brine Tank / Brine Well Leak
| Error Code | Symptom | Fault Type | Guide |
|---|---|---|---|
| Err 01 |
Control panel displays “Err 01” and regeneration will not start automatically.
|
Turbine / Flow Sensor Failure | View Details |
| Err 02 |
Display shows “Err 02” and the unit will not advance through regeneration cycles.
|
Motor or Cam Position Fault | View Details |
| Err 03 |
Control displays “Err 03” and the softener is stuck in one regeneration position (e.g., brine draw or backwash).
|
Valve Position Switch / Encoder Error | View Details |
| Err 04 |
Display shows “Err 04” and the time or regeneration settings will not save or stay accurate.
|
Control Board Memory / Programming Fault | View Details |
| Err 05 |
Display shows “Err 05” and the unit will not initiate or complete brine draw.
|
Brine Valve / Injector Blockage | View Details |
| Err 06 |
Display shows “Err 06” and the unit reports a salt system problem or low salt even when salt is present.
|
Salt Level Sensor / Brine Well Sensor Fault | View Details |
| Err 07 |
Display shows “Err 07” and the unit indicates a high flow or leak condition even when no water is running.
|
False High-Flow / Leak Detection from Flow Sensor | View Details |
| Err 08 |
Display shows “Err 08” and the softener will not recognize when the brine tank is refilled or when regeneration completes.
|
Regeneration Completion / Sensor Feedback Error | View Details |
| Err 09 |
Display shows “Err 09” and the unit reports a power or low-voltage fault.
|
Low Voltage / Power Supply Error | View Details |
| Err 10 |
Display shows “Err 10” and the unit indicates an internal sensor or configuration error.
|
Internal Control Self-Test Failure | View Details |
| Lo Brine |
Display shows “Lo Brine” or “Check Brine” and regeneration is ineffective.
|
Insufficient Brine Concentration | View Details |
| Lo Salt |
Display shows “Lo Salt” or a salt icon, and an audible alarm may sound.
|
Low Salt Level Warning | View Details |
| No Flow |
Display shows “No Flow” even when water is being used in the home, or unit never regenerates on demand.
|
Flow Meter Not Registering Usage | View Details |
| Service |
Display shows “Service” or “Call for Service” without a numeric code, and softener may not regenerate.
|
General System Fault / Service Reminder | View Details |
| – |
Brine tank fills with water and may overflow.
|
Brine Tank Overfill | View Details |
| – |
Salt forms a hard crust (bridge) in the brine tank and the softener stops softening.
|
Salt Bridging | View Details |
| – |
Salt turns into a thick mush at the bottom of the brine tank and brine draw becomes unreliable.
|
Salt Mushing | View Details |
| – |
Softener appears to regenerate too frequently (daily or more) without obvious reason.
|
Excessive Regeneration Frequency | View Details |
| – |
Softener backwashes to drain but does not draw brine or refill properly.
|
Partial Regeneration Function | View Details |
| – |
Softener causes noticeable drop in water pressure throughout the home.
|
Flow Restriction Through Softener | View Details |
| – |
Softener causes water hammer or banging pipes when it changes cycles.
|
Rapid Valve Shifts / High Flow Rate Shock | View Details |
| – |
Softener does not regenerate at the programmed time (e.g., 2 AM) and appears to skip cycles.
|
Regeneration Not Initiating | View Details |
| – |
Softener drains continuously to the drain line, even when not regenerating.
|
Valve Not Sealing in Service Position | View Details |
| – |
Softener emits a constant humming noise even when not regenerating.
|
Transformer or Motor Hum | View Details |
| – |
Softener is stuck in regeneration and does not return to service; water may be hard or unavailable.
|
Valve Stuck Mid-Cycle | View Details |
| – |
Softener makes loud clicking, grinding, or knocking noises during regeneration.
|
Mechanical Drive Noise / Gear Damage | View Details |
| – |
Softener resin is found in household plumbing fixtures (small amber beads in aerators).
|
Resin Loss into Plumbing | View Details |
| – |
Softener uses no salt; salt level in the brine tank never drops.
|
No Brine Draw During Regeneration | View Details |
| – |
Softener uses too much salt; salt level drops very quickly and salt consumption is higher than expected.
|
Excessive Brine Refill / Over-Regeneration | View Details |
| – |
Softener will not power on; display is blank.
|
No Power to Control Head | View Details |
| – |
Softener will not start a manual regeneration when the button is pressed.
|
Manual Regeneration Control Failure | View Details |
| – |
Water has a salty taste after regeneration.
|
Incomplete Rinse / Excess Brine Carryover | View Details |
| – |
Water has an unusual odor (musty, rotten egg, or metallic) after installing or servicing the softener.
|
Odor Related to Softener or Plumbing | View Details |
| – |
Water is intermittently hard, especially just before scheduled regeneration.
|
Undersized System / Incorrect Capacity Programming | View Details |
| – |
Water remains hard even though the AO Smith water softener appears to run and regenerate normally.
|
Insufficient Softening Capacity / Resin Exhaustion | View Details |
| – |
Water softener is leaking from around the control valve head.
|
Control Valve Head Leak | View Details |
| – |
Water softener is leaking from the brine tank or around the brine well.
|
Brine Tank / Brine Well Leak | View Details |
No matching codes found
Advertisements