Display shows E9 and unit appears to be locked or frozen

Safety: Unplug the transformer before removing any covers.

• Soft reset: Press and hold the appropriate buttons (refer to your WaterBoss manual; often a combination like Regen + Up) for 10–15 seconds to clear the lock.
• Power cycle: Unplug the transformer for 5 minutes, then plug back in. Recheck operation.
• Inspect keypad: Ensure no buttons are physically stuck or jammed. Clean around the buttons with a dry cloth.
• If E9 returns frequently: The control board or keypad may be failing and should be replaced.