E20 error and the unit indicates an internal leak or continuous flow when no water is being used.

Safety first: Unplug the softener and place it in BYPASS. Depressurize by opening a downstream faucet before disassembling the valve.

Step-by-step:

• 1. Confirm no fixtures are running: Ensure all taps, toilets, and appliances are off. If the flow meter still shows flow, an internal leak is likely.
• 2. Inspect external plumbing: Check for leaks around the bypass and tank connections that could mimic internal flow.
• 3. Open control valve: Remove the control head cover and access the rotor and seal pack (refer to AquaHouse service manual). Note the orientation of parts.
• 4. Clean and inspect seals: Remove the rotor and seal/spacer stack. Clean all parts and inspect for grooves, tears, or warping. Replace with a new AquaHouse seal and spacer kit if worn.
• 5. Inspect valve body: Look for cracks or erosion in the valve body. Replace the entire AquaHouse control valve body if damaged.
• 6. Reassemble and test: Reinstall components, restore SERVICE mode and power, and verify that flow drops to zero when no water is used.