No programming required. Salt and water efficient, Soft water on demand 24 hours per day Automatic regeneration. Low flow metering measures low water flows.Highest flow rates. Two Types of machine: High Flow (H.F.) 2020c Suitable for unvented systems such as the MegaFlow or combination boiler systems with low pressure. High Efficiency ( H.E.) suitable for open vented systems, eg. Loft storage tank,15mm pipe work. Seven Years Manufacturers warranty on parts.