Display shows “Err 16” and unit fails to initiate scheduled regeneration

Safety: No internal valve work is required for this fault; do not open pressurized plumbing.

Steps:

• 1. Set time of day: Enter the Sterling control programming and verify the current time is set correctly, including AM/PM if applicable.
• 2. Check regeneration mode: Confirm the unit is set to metered or time-clock mode as desired, and that a regeneration time is programmed.
• 3. Verify power stability: If frequent outages occur, consider a surge protector or UPS for the softener.
• 4. Observe operation: After correcting settings, monitor whether the unit regenerates at the next scheduled time.
• 5. Replace board if needed: If the clock drifts significantly or stops, the main control board may need replacement.