The UV Guard Armour 3 is a whole-house UV water steriliser designed for medium-sized domestic properties and light commercial applications. Delivering a UV dose of 40 mJ/cm² – the NSF/ANSI Standard 55 Class A benchmark – this UV water treatment system provides full-spectrum protection against bacteria, viruses, and chlorine-resistant parasites including Cryptosporidium and Giardia. At peak output, the Armour 3 treats up to 70 litres per minute through RO-treated water, or around 53 litres per minute on standard UK mains supply. That's comfortably enough for a typical 2–4 bedroom home with up to two bathrooms — making it one of the most versatile UV water filter systems in the Armour range for UK domestic properties on borehole or private water supplies. Manufactured in Australia by UV Guard, a specialist UV water treatment company with over 15 years' experience, the Armour 3 shares the same commercial-grade build quality as every model in the range. Every system is built around a WaterMark-certified food-grade 316L stainless steel reactor — the low-carbon variant that offers superior weld corrosion resistance and longevity compared to the standard 304 grade stainless steel used in many competing UV steriliser products. Why 40 mJ/cm² Matters for UV Water Treatment Many UV water purifier systems on the market are rated at just 30 mJ/cm² — adequate for basic bacterial disinfection but below the internationally recognised NSF/ANSI Standard 55 Class A threshold. The Armour 3 is designed to deliver 40 mJ/cm² across its rated flow range, providing a 4-log reduction (99.99%) in bacteria, viruses, and protozoan cysts. This is the standard recommended for drinking water, process water, warm water recirculation, and medical applications. If you're sourcing a UV water filter for home use on a borehole, spring, or private water supply, the difference between 30 and 40 mJ/cm² is the difference between basic bacterial reduction and certified protection against the full spectrum of waterborne pathogens — including Cryptosporidium, which is resistant to chlorine and a common concern on private water supplies across the UK. UV Water Steriliser Flow Rate Capacity Flow rates vary depending on your water source and its UV transmittance (UVT). The table below shows the Armour 3's performance at both the standard 30 mJ/cm² dose and the higher NSF 55 Class A dose of 40 mJ/cm²: Water Source Estimated UVT Flow @ 30 mJ/cm² Flow @ 40 mJ/cm² Reverse osmosis treated water 98% 94 litres/min (5.63 m³/hr) 70 litres/min (4.22 m³/hr) UK mains / town water 85% 70 litres/min (4.21 m³/hr) 53 litres/min (3.16 m³/hr) Filtered borehole or rainwater 80% 63 litres/min (3.76 m³/hr) 47 litres/min (2.82 m³/hr) Key Features Food-Grade 316L Stainless Steel Reactor — Low-carbon marine-grade steel with superior weld corrosion resistance for long-lasting durability in demanding installations WaterMark Certified — Independently verified for safe use in drinking water applications 40 mJ/cm² UV Dose — NSF/ANSI Standard 55 Class A level disinfection, destroying 99.99% of bacteria, viruses, Cryptosporidium, and Giardia 55W UV Lamp — Efficient low-pressure lamp technology with proven germicidal performance at 254nm, delivering whole-house protection at moderate running cost 1" BSP Connections — UK-standard fittings with both L and Z flow configurations available from a single unit for maximum installation flexibility Transparent Lamp Window — Built-in visual indicator glows when the UV lamp is operational, providing at-a-glance confirmation without opening the system UV Intensity Sensor Port — Dedicated viewport for optional UV intensity monitoring, allowing real-time measurement of UV dose delivery Adjustable Mounting Brackets — Stainless steel brackets with rubber inserts for flexible horizontal or vertical installation Upgradeable Platform — Optional UV intensity monitoring, BMS fault connections, SMS alarm modules, temperature management, and more UV Water Treatment System Controller Options The Armour 3 is available with several controller options to suit different installation requirements: Basic Indoor Controller (40089) — Entry-level option for simple domestic installations. Features lamp on/off LEDs. Indoor Controller (40090) — For sheltered installations. Features lamp on/off LEDs, audible lamp fail alarm, digital lamp life timer, and BMS fault connections. Weatherproof Controller (40091) — IP65 rated for outdoor or exposed installations. Same feature set as the basic indoor controller with full weather protection. Ideal for borehole water treatment installations, agricultural sites, and exposed plant rooms. Indoor Controller with UV Intensity Monitoring (40090UVi) — Full-featured controller with real-time UV intensity monitoring and 4-20mA output for integration with building management systems. Weatherproof PLC Controller (50081-NC) — IP65 rated with full PLC control. BMS fault connections and UV intensity monitoring available as optional extras.
