Display shows “Err 06” and the unit reports a salt system problem or low salt even when salt is present.

Safety first: Disconnect power. Do not reach into the brine tank with power connected.

Inspect the salt level sensor:

• Locate the sensor: Many AO Smith softeners use a float or electronic sensor in the brine well (the small tube inside the salt tank).
• Remove the brine well cover: Lift off the cover and carefully pull out the float/sensor assembly.
• Clean the sensor: Remove salt crust, sludge, or bridging from the float and shaft. Rinse with warm water until the float moves freely.
• Check wiring: Follow the sensor cable to the control head. Ensure the connector is fully seated and not corroded.
• Verify installation height: Confirm the sensor is installed at the correct height per the AO Smith manual; if set too high or too low, it may misread salt level.
• Reset alarm: Restore power and clear the error or salt alarm according to the user manual, then monitor for recurrence.

If the error returns: Replace the salt level / brine well sensor assembly. If the model uses a simple float, replace the entire float kit.