Display shows “Err 09” and the unit indicates a power or memory fault; settings may reset unexpectedly.

Safety first: Unplug the power supply before inspecting wiring.

Power quality checks:

• Confirm the softener is plugged into a properly grounded outlet not shared with large inductive loads (e.g., well pump, air compressor) if possible.
• Consider using a surge protector rated for the transformer.
• Check the transformer output with a multimeter to ensure stable voltage.

Reset and reprogram:

• Perform a full controller reset according to the Kinetico manual (often involves holding specific buttons while powering up).
• Re-enter all hardness, capacity, and time settings.

Resolution: If Err 09 returns after a proper reset and stable power is confirmed, the controller board memory is likely failing and the board should be replaced by a qualified technician.