Display shows E18 and unit logs frequent power errors or brownout conditions.

Safety first: Use caution when working around electrical outlets. Unplug the adapter before inspection.

• Verify adapter: Check the label on the AC adapter and confirm voltage and polarity match Crystal Quest specifications. Replace with an OEM Crystal Quest power supply if incorrect or suspect.
• Inspect jack: Ensure the power plug fits snugly into the valve's power jack. If loose or intermittent, the jack or board may be damaged.
• Dedicated outlet: Plug the softener into a dedicated, non-switched outlet. Avoid extension cords and power strips.
• Board replacement: If E18 persists with a known-good adapter and outlet, replace the Crystal Quest main control board due to internal regulator failure.