E13 displayed and unit will not accept new programming or buttons are unresponsive

Safety first: Unplug the softener before removing the front panel.

• Inspect keypad surface: Check for cracks, water stains, or physical damage to the keypad overlay. Dry any visible moisture.
• Check ribbon cable: Remove the front panel and locate the ribbon cable or harness connecting the keypad to the main board. Reseat the connector and ensure it is fully latched.
• Test individual buttons: With power restored, press each button and observe the display. If some buttons work and others do not, the keypad membrane is likely failing and should be replaced.
• Replace user interface: Install a new Watersoft user interface / keypad assembly, transferring any mounting hardware. Avoid overtightening screws to prevent warping the panel.

If a new keypad does not resolve E13, the keypad input circuitry on the main board may be defective.