Monarch SI-28 Scaleout Inhibitor 28mm WRAS Approved High Flow Catalytic Core Scale Prevention for Boiler and Shower

The Monarch SI-28 Scaleout Inhibitor is built for 28mm water systems in large households (6+ people), providing continuous protection from limescale buildup using a patented food-grade catalytic core housed in a stainless steel body.

This WRAS-approved unit protects boilers, water tanks, showers, kettles, washing machines, and dishwashers by removing existing scale and preventing new deposits. With no chemicals, no electricity, and no ongoing maintenance, the SI-28 offers fit-and-forget simplicity and long-term reliability.

Its self-cleaning design ensures the core operates at peak efficiency year-round, and installation is simple across all pipe types—copper, PVC, or galvanized. Proudly made in the UK and backed by a 10-year parts warranty, the Monarch SI-28 is ideal for energy savings and plumbing system longevity.

Key Features

• Patented Catalytic Core – Advanced internal core prevents and removes limescale buildup
• WRAS Approved Build – Compliant with UK water regulations for safety and durability
• High Flow 28mm Compatibility – Designed for large domestic systems with up to 62 lpm flow
• Self-Cleaning Action – Keeps internal core operating at maximum efficiency
• Zero Maintenance Required – No electricity, chemicals, or servicing needed
• 10-Year Parts Warranty – Backed by Monarch’s long-term reliability guarantee

Applications

• Boiler and Heating System Protection – Ideal for large domestic systems running on 28mm pipework
• Full Household Scaling Control – Protects showers, taps, and water outlets from scale buildup
• Appliance Scale Prevention – Supports longer lifespan and better performance of dishwashers, kettles, and washing machines

Technical Specifications: