E20 error and the unit indicates resin exhaustion too frequently

Safety: No special electrical or plumbing work is required for basic checks, but unplug the unit before opening the valve head.

• Check hardness setting: Confirm the programmed hardness matches your actual water hardness (test with a reliable kit or lab report).
• Verify capacity: Ensure the grain capacity setting matches the Foridra resin tank size and salt dosage.
• Inspect resin: If water remains hard soon after regeneration, the resin may be fouled with iron or organics. Consider cleaning with a resin cleaner recommended for Foridra systems.
• Check flow meter: Ensure the Foridra flow sensor is not over-counting due to electrical noise or miswiring (see E05).