Controller display shows “Err 02” and unit does not track time or initiate scheduled regeneration.

Safety first: Disconnect the power supply to the controller before handling any wiring.

Basic checks:

• Verify the power supply transformer is firmly plugged into a working outlet. Test the outlet with another device.
• Inspect the low-voltage cable from the transformer to the controller for cuts, kinks, or loose connectors.
• Unplug the transformer for 2–3 minutes to perform a soft reset of the controller, then plug it back in.
• Reprogram the time of day and regeneration settings according to the Kinetico controller manual.

Advanced checks (if comfortable):

• Use a multimeter to verify the transformer output matches the rating on the label (typically 24V AC). Replace the transformer if voltage is low or unstable.
• If Err 02 reappears immediately after reset and power is stable, the controller board is likely defective.

Resolution: In most cases, Err 02 requires replacement of the controller/timer module. This involves disconnecting multiple harnesses and transferring settings, and should be done by a qualified technician to preserve warranty and programming.