Control panel displays “Err 01” and regeneration will not start automatically.

Safety first: Unplug the softener or switch off the dedicated breaker. Close the inlet water valve and open a nearby softener-fed faucet to relieve pressure.

Steps to check and clear the turbine sensor:

• Access the valve head: Remove the top cover of the AO Smith softener to expose the control valve and brine well area.
• Locate the turbine/flow sensor: On most AO Smith softeners, the turbine assembly is in the outlet side of the control valve body, often under a small plastic cap with a wire harness attached.
• Inspect for debris: Gently pull out the turbine assembly. Look for sand, iron sludge, or plastic shavings that may be jamming the wheel. Rinse the turbine and housing with clean water.
• Check turbine rotation: Spin the turbine wheel with your finger; it should move freely without sticking. If the wheel is cracked, swollen, or seized, it must be replaced.
• Inspect wiring: Follow the small harness from the turbine sensor to the control board. Ensure the connector is fully seated and there are no broken or corroded pins.
• Reassemble and test: Reinstall the turbine, restore water and power, then run a manual regeneration. Watch the display to see if the error clears and if flow is being registered (some models show flow rate).

If the error persists: Replace the complete turbine/flow sensor assembly. If a new sensor does not resolve the issue, the control board may be defective and should be replaced by a qualified technician.