E20 displayed and the unit reports an internal valve leak or cross-leak condition.

Safety first: Unplug the unit and close inlet and outlet valves. Relieve pressure by opening a faucet.

• Check for hardness leakage: Test water hardness at a faucet after the softener. If water is hard even after regeneration, internal leakage is likely.
• Inspect rotor and seals: Remove the control head cover and access the rotor disc and seal/spacer stack. Look for scoring, cracks, or flattened seals.
• Clean valve body: Wipe the valve seats and internal surfaces with a clean, lint-free cloth to remove debris.
• Replace seal kit: Install a new AquaSoft rotor seal and spacer kit, and replace the rotor disc if damaged.
• Reassemble and test: Reinstall the control head, restore water and power, and run a manual regeneration. Retest hardness to confirm the leak is resolved and E20 clears.