Display shows E4 and system will not run a regeneration cycle

Safety first: Put the unit in BYPASS and unplug power. Wear gloves and eye protection when working around salt and brine.

Steps to troubleshoot E4 (brine system):

• 1. Check brine level: Open the Aquasana brine tank. Ensure there is adequate water above the salt bed (typically a few inches). If the tank is full of solid salt with a hollow underneath, you have a salt bridge.
• 2. Break salt bridge: Use a broom handle or plastic rod to gently push down through the salt to break any hardened crust. Do not use sharp metal tools that can puncture the tank.
• 3. Inspect brine line: Follow the brine line from the brine tank to the control head. Straighten any kinks and ensure the line is not pinched. Remove the line at the control head and blow through it to confirm it is clear.
• 4. Clean injector/venturi: On the Aquasana control head, locate the injector/venturi assembly (usually under a cap). Remove it carefully, noting O-ring positions. Soak the injector and screen in warm water with a little vinegar to dissolve scale, then rinse thoroughly.
• 5. Reassemble and test: Reinstall the injector and brine line, restore water from BYPASS slowly, then plug in power and run a manual regeneration. Observe whether brine is drawn from the tank during the brine draw stage.
• 6. If E4 persists: The brine valve or internal passages may be damaged. Replace the brine injector/venturi kit or the complete Aquasana control valve head if necessary.