Display shows “Err 13” and the unit will not enter regeneration when the button is pressed.

Safety first: No internal wet components need to be opened for this fault. You may leave the unit powered.

Steps to resolve:

• 1. Check for lock icon: Look for any lock or key symbol on the display indicating a child lock or keypad lock. Follow the manual to disable it (often by holding specific buttons for several seconds).
• 2. Verify installer settings: Enter the installer menu and confirm that manual regeneration is not disabled. Re-enable if necessary.
• 3. Test keypad: Try other buttons to see if they respond. If only the regen button fails, the keypad membrane may be damaged and require replacement.
• 4. Board response: If the keypad is good but the board does not start regeneration, the control board may be faulty and should be replaced.