Grundfos STN-2.0 Twin Shower Negative Pump 98284259 for Gravity-Fed Systems
Description
Negative head shower pump - for gravity-fed systems where the outlet sits below the cold water tank 2.0 bar rated pressure boost - up to 20 m maximum head Twin brass impellers with regenerative impeller design for reliable performance WRAS approved - certified safe for use with drinking water systems 510 W rated power input - rated current 2.2 A at 230 V / 50 Hz Flow rate up to 50 litres per minute Built-in thermal motor protection - pump stops automatically if it overheats IPX2 enclosure rating with anti-vibration feet fitted as standard Noise level 55-65 dBA at 1 metre Supplied with four flexible stainless steel braided connection hoses Manufacturer warranty: 2 years Dimensions: 287 x 309 x 232 mm Grundfos STN-2.0 B Twin Brass Negative Head Shower Pump Purpose-built for gravity-fed systems: The 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. Regenerative impeller design: The 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. Durable brass construction with built-in protection: The 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 re 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. WRAS approved and CE certified: The 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. Shop the full All Showers range from Heavins.ie, your local bathroom and plumbing specialist serving customers across Ireland. Key Features Negative Head Configuration - flow-switch activation only, correct for gravity-fed systems where the outlet is below the cold water tank. Regenerative Impeller Design - twin brass impellers overcome air pockets and maintain pressure through complex pipework routes. 2.0 Bar Rated Pressure - maximum head of 20 m, rated head 15.1 m, suitable for single or multiple shower outlets. WRAS Approved - approval number 1209052, certified safe for potable water systems in the UK and Ireland. Built-in Thermal Motor Protection - stops the pump automatically if the motor temperature exceeds safe limits. IPX2 Enclosure Class - rated for the damp environments typical of airing cupboards and hot press installations. Anti-Vibration Feet - fitted as standard to reduce noise transmission through floors and pipework. Silicon Carbide Seals - long-life shaft seals for quiet, reliable continuous-duty operation. 22 mm Push-Fit Connections - G ¾ inch inlet and outlet with PN 6 pressure rating, compatible with standard flexible hose fittings. Stainless Steel Braided Hoses Included - four flexible, corrosion-resistant connection hoses supplied in the box. Specifications Model: Grundfos STN-2.0 B GBQP (Product No. 98284259) Pump type: Regenerative, twin impeller Impeller material: Brass Head configuration: Negative head only Rated pressure: 2.0 bar Maximum head: 20 m Rated head: 15.1 m Minimum static head: 1 m Maximum flow rate: 50 litres/min (0.6 m³/h) Minimum flow rate: 5 litres/min Power input (P1 max): 510 W Rated voltage: 230 V / 50 Hz Rated current: 2.2 A Cable length: 1.5 m Motor type: Induction Enclosure class: IPX2 (IEC 34-5) Insulation class: F (IEC 85) Liquid temperature range: 5-60 °C Ambient temperature range: 0-40 °C Maximum operating pressure: 6 bar Noise level: 55-65 dBA at 1 m Inlet/outlet connections: G ¾ inch push-fit (PN 6) Activation: Flow switch (no pressure switch) Certifications: CE, WRAS (approval no. 1209052) Standard: ISO 9906:2012 3B, Model A Colour: Black Net weight: 9.5 kg Dimensions (HxWxD): 287 x 309 x 232 mm Manufacturer warranty: 2 years What's Included in the Box Grundfos STN-2.0 B negative head