“Err 05” appears and the display may be blank or frozen; softener does not respond to button presses.

Safety first: Unplug the softener before removing the control panel. Avoid static discharge by touching a grounded metal object before handling circuit boards.

• Power cycle: Unplug the unit for 10 minutes, then plug it back in. If Err 05 or a frozen display returns immediately, continue with inspection.
• Inspect control panel: Remove the top cover and gently lift the control panel assembly. Check for signs of moisture intrusion, corrosion, or insect damage. If the keypad area is wet, dry it thoroughly and identify the source of the leak (often a loose cover or condensation).
• Check ribbon cable and connectors: Ensure the flat ribbon cable between the display/keypad and the main control board is fully seated and not damaged. Reseat connectors carefully.
• Look for burnt components: Examine the main control board for burnt spots, bulging capacitors, or cracked solder joints. Power surge damage often leaves visible marks.
• Replacement: If the keypad membrane is unresponsive or the board shows damage, replace the electronic control board assembly (often sold as a complete display/control module for Morton units). Transfer any programming settings as needed.
• Reassemble and test: Reinstall the panel, restore power, and reprogram time, hardness, and regeneration settings. Verify that all buttons respond and that Err 05 is cleared.