E15 displayed and the unit indicates a resin tank pressure or leak fault (on models with pressure sensor).

Safety first: Turn off water supply and depressurize the system before inspecting for leaks. Water under pressure can cause injury.

• Inspect for visible leaks: Check around the Clearwater control valve, tank neck, and plumbing unions for drips or spray.
• Tighten tank adapter: Gently tighten the valve-to-tank adapter ring if loose. Do not overtighten, as this can crack the tank neck.
• Check O-rings: Remove the valve from the tank (after depressurizing) and inspect the large tank O-ring for cuts or flattening. Replace if damaged.
• Verify sensor: If equipped, inspect the pressure sensor port and wiring. Ensure no leaks at the sensor fitting.

After correcting leaks, restore water slowly and watch for further leakage. If E15 continues with no leaks present, the Clearwater pressure sensor may be faulty.