E13 error and the unit fails to enter regeneration at the programmed time.

Safety first: No high-voltage work is required for basic checks.

• Set correct time: Enter the time-of-day setting on the AquaSoft control and set the correct current time and regeneration time.
• Check power stability: Ensure the softener is plugged into a non-switched outlet that is not controlled by a wall switch or timer.
• Inspect backup battery (if present): Some AquaSoft models have an internal coin-cell or rechargeable battery. Access the control board and replace the battery with the specified type if it is depleted.
• Factory reset: Perform a control reset and reprogram all settings. Monitor whether the clock keeps accurate time over 24–48 hours.
• Replace control board: If the clock continues to drift or E13 returns, the main control board's clock circuit is likely defective and should be replaced.