{"product_id":"grundfos-stn-2-0-twin-brass-shower-negative-pump-98284259","title":"Grundfos STN-2.0 Twin Brass Shower Negative Pump | 98284259","description":"\u003cul\u003e\n\u003cli\u003eNegative head shower pump - for gravity-fed systems where the outlet sits below the cold water tank\u003c\/li\u003e\n\u003cli\u003e2.0 bar rated pressure boost - up to 20 m maximum head\u003c\/li\u003e\n\u003cli\u003eTwin brass impellers with regenerative impeller design for reliable performance\u003c\/li\u003e\n\u003cli\u003eWRAS approved - certified safe for use with drinking water systems\u003c\/li\u003e\n\u003cli\u003e510 W rated power input - rated current 2.2 A at 230 V \/ 50 Hz\u003c\/li\u003e\n\u003cli\u003eFlow rate up to 50 litres per minute\u003c\/li\u003e\n\u003cli\u003eBuilt-in thermal motor protection - pump stops automatically if it overheats\u003c\/li\u003e\n\u003cli\u003eIPX2 enclosure rating with anti-vibration feet fitted as standard\u003c\/li\u003e\n\u003cli\u003eNoise level 55-65 dBA at 1 metre\u003c\/li\u003e\n\u003cli\u003eSupplied with four flexible stainless steel braided connection hoses\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer warranty:\u003c\/strong\u003e 2 years\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 287 x 309 x 232 mm\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eGrundfos STN-2.0 B Twin Brass Negative Head Shower Pump\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003ePurpose-built for gravity-fed systems:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe Grundfos STN-2.0 B (Product No. 98284259) is a negative head shower pump designed specifically for gravity-fed hot water systems where the shower outlet is positioned below the cold water storage tank. It is the correct replacement for any existing 3 bar negative pump - identifiable by the presence of air tanks attached to the existing unit - and suits homes where low mains pressure results in a disappointing shower experience.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRegenerative impeller design:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe STN-2.0 B uses a regenerative impeller design with twin brass impellers to deliver consistent pressure across the full plumbing route. Unlike standard centrifugal pumps, the regenerative type is equipped to overcome air pockets and maintains performance even where the pipework includes multiple bends or elbows. The rated pressure is 2.0 bar, with a maximum head of 20 m and a minimum static head requirement of just 1 m.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eDurable brass construction with built-in protection:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe pump housing and both impellers are manufactured in brass, contributing to long-term durability in a wet environment. A built-in thermal protection system monitors the motor continuously and stops the pump immediately if it reaches an unsafe operating temperature. Silicon carbide seals support quiet, long-life operation, and the anti-vibration feet fitted as standard reduce transmitted noise to floors and pipework.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eWRAS approved and CE certified:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe STN-2.0 B carries both CE certification and WRAS approval (Water Regulations Advisory Scheme, approval number 1209052), confirming it has passed independent testing for use with potable water systems. It conforms to ISO 9906:2012 3B, Model A curve tolerance standards. The pump activates via a flow switch - no pressure switch is fitted - which is the correct configuration for negative head installations. G ¾ inch push-fit connections are used at both inlet and outlet, accepting standard 22 mm flexible hoses.\u003c\/p\u003e\n\n\u003cp\u003eShop the full \u003ca href=\"\/collections\/all-showers-bathroom-studio\" style=\"color: #2B00FF;\"\u003eAll Showers range\u003c\/a\u003e from Heavins.ie, your local bathroom and plumbing specialist serving customers across Ireland.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cstrong\u003eNegative Head Configuration\u003c\/strong\u003e - flow-switch activation only, correct for gravity-fed systems where the outlet is below the cold water tank.\u003cbr\u003e\n\u003cstrong\u003eRegenerative Impeller Design\u003c\/strong\u003e - twin brass impellers overcome air pockets and maintain pressure through complex pipework routes.\u003cbr\u003e\n\u003cstrong\u003e2.0 Bar Rated Pressure\u003c\/strong\u003e - maximum head of 20 m, rated head 15.1 m, suitable for single or multiple shower outlets.\u003cbr\u003e\n\u003cstrong\u003eWRAS Approved\u003c\/strong\u003e - approval number 1209052, certified safe for potable water systems in the UK and Ireland.\u003cbr\u003e\n\u003cstrong\u003eBuilt-in Thermal Motor Protection\u003c\/strong\u003e - stops the pump automatically if the motor temperature exceeds safe limits.\u003cbr\u003e\n\u003cstrong\u003eIPX2 Enclosure Class\u003c\/strong\u003e - rated for the damp environments typical of airing cupboards and hot press installations.\u003cbr\u003e\n\u003cstrong\u003eAnti-Vibration Feet\u003c\/strong\u003e - fitted as standard to reduce noise transmission through floors and pipework.\u003cbr\u003e\n\u003cstrong\u003eSilicon Carbide Seals\u003c\/strong\u003e - long-life shaft seals for quiet, reliable continuous-duty operation.\u003cbr\u003e\n\u003cstrong\u003e22 mm Push-Fit Connections\u003c\/strong\u003e - G ¾ inch inlet and outlet with PN 6 pressure rating, compatible with standard flexible hose fittings.\u003cbr\u003e\n\u003cstrong\u003eStainless Steel Braided Hoses Included\u003c\/strong\u003e - four flexible, corrosion-resistant connection hoses supplied in the box.\u003cbr\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eModel: Grundfos STN-2.0 B GBQP (Product No. 98284259)\u003c\/li\u003e\n\u003cli\u003ePump type: Regenerative, twin impeller\u003c\/li\u003e\n\u003cli\u003eImpeller material: Brass\u003c\/li\u003e\n\u003cli\u003eHead configuration: Negative head only\u003c\/li\u003e\n\u003cli\u003eRated pressure: 2.0 bar\u003c\/li\u003e\n\u003cli\u003eMaximum head: 20 m\u003c\/li\u003e\n\u003cli\u003eRated head: 15.1 m\u003c\/li\u003e\n\u003cli\u003eMinimum static head: 1 m\u003c\/li\u003e\n\u003cli\u003eMaximum flow rate: 50 litres\/min (0.6 m³\/h)\u003c\/li\u003e\n\u003cli\u003eMinimum flow rate: 5 litres\/min\u003c\/li\u003e\n\u003cli\u003ePower input (P1 max): 510 W\u003c\/li\u003e\n\u003cli\u003eRated voltage: 230 V \/ 50 Hz\u003c\/li\u003e\n\u003cli\u003eRated current: 2.2 A\u003c\/li\u003e\n\u003cli\u003eCable length: 1.5 m\u003c\/li\u003e\n\u003cli\u003eMotor type: Induction\u003c\/li\u003e\n\u003cli\u003eEnclosure class: IPX2 (IEC 34-5)\u003c\/li\u003e\n\u003cli\u003eInsulation class: F (IEC 85)\u003c\/li\u003e\n\u003cli\u003eLiquid temperature range: 5-60 °C\u003c\/li\u003e\n\u003cli\u003eAmbient temperature range: 0-40 °C\u003c\/li\u003e\n\u003cli\u003eMaximum operating pressure: 6 bar\u003c\/li\u003e\n\u003cli\u003eNoise level: 55-65 dBA at 1 m\u003c\/li\u003e\n\u003cli\u003eInlet\/outlet connections: G ¾ inch push-fit (PN 6)\u003c\/li\u003e\n\u003cli\u003eActivation: Flow switch (no pressure switch)\u003c\/li\u003e\n\u003cli\u003eCertifications: CE, WRAS (approval no. 1209052)\u003c\/li\u003e\n\u003cli\u003eStandard: ISO 9906:2012 3B, Model A\u003c\/li\u003e\n\u003cli\u003eColour: Black\u003c\/li\u003e\n\u003cli\u003eNet weight: 9.5 kg\u003c\/li\u003e\n\u003cli\u003eDimensions (HxWxD): 287 x 309 x 232 mm\u003c\/li\u003e\n\u003cli\u003eManufacturer warranty: 2 years\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat's Included in the Box\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eGrundfos STN-2.0 B negative head shower pump\u003c\/li\u003e\n\u003cli\u003e4 x flexible stainless steel braided connection hoses (22 mm push-fit)\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eSetup and Care\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eInstallation guidance:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe STN-2.0 B is designed for gravity-fed hot water systems where the shower outlet is positioned below the cold water storage tank - confirmed by the presence of air tanks on any existing pump. G ¾ inch push-fit connections at both inlet and outlet accept the supplied 22 mm stainless steel braided hoses. Installation by a qualified plumber is recommended to ensure correct orientation and comply with local water regulations.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePositioning and ventilation:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe pump should be installed in a dry, well-ventilated location such as an airing cupboard or hot press, with the anti-vibration feet resting on a firm, level surface. Keep the area around the pump clear to allow adequate airflow to the motor. The IPX2 enclosure rating means the pump is splash-resistant but should not be installed in direct contact with water.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRoutine maintenance:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eInspect the stainless steel braided hoses and push-fit connections periodically for signs of wear or mineral build-up. The filter washers fitted to the hose connections should be checked and cleaned as part of any routine service. Where water hardness is a concern, descaling the hoses at regular intervals will help maintain flow performance.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRunning the pump correctly:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe STN-2.0 B is activated by flow only - open the shower valve before expecting the pump to start. Never run the pump dry or against a closed valve for extended periods, as the built-in thermal protection is a safeguard rather than a substitute for correct operation. The pump is rated for continuous duty within its specified liquid temperature range of 5-60 °C.\u003c\/p\u003e","brand":"Grundfos","offers":[{"title":"Default Title","offer_id":57724913582453,"sku":"5700311402573","price":669.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0614\/5261\/5816\/files\/heavins-grundfos-stn-2-0-twin-brass-shower-negative-pump-98284259-01.jpg?v=1793810694","url":"https:\/\/www.heavins.ie\/products\/grundfos-stn-2-0-twin-brass-shower-negative-pump-98284259","provider":"Heavins","version":"1.0","type":"link"}