{"product_id":"grundfos-stn-3-0-bar-brass-negative-twin-impeller-shower-pump-98284261","title":"Grundfos STN 3.0 Bar Brass Negative Twin Impeller Shower Pump | 98284261","description":"\u003cul\u003e\n\u003cli\u003eTwin impeller shower pump - boosts both hot and cold water simultaneously\u003c\/li\u003e\n\u003cli\u003e3.0 bar pressure rating - maximum head of 30 metres\u003c\/li\u003e\n\u003cli\u003eNegative head design - for systems where the cold tank sits below the shower outlet\u003c\/li\u003e\n\u003cli\u003eBrass impellers and housing - heavy-duty construction for long service life\u003c\/li\u003e\n\u003cli\u003eRegenerative pump type - handles air pockets effectively\u003c\/li\u003e\n\u003cli\u003e52 litres per minute maximum flow rate\u003c\/li\u003e\n\u003cli\u003eWRAS approved - safe for use with drinking water systems\u003c\/li\u003e\n\u003cli\u003e55 dB operating noise level with anti-vibration feet and silicon carbide seals\u003c\/li\u003e\n\u003cli\u003eBuilt-in thermal protection stops the motor if it overheats\u003c\/li\u003e\n\u003cli\u003eIPX2 rated - splash resistant enclosure\u003c\/li\u003e\n\u003cli\u003eContinuously rated - suitable for domestic and light commercial use\u003c\/li\u003e\n\u003cli\u003e710W input power, 230V mains, ¾ inch BSP connections\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer warranty:\u003c\/strong\u003e 5 years\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDimensions:\u003c\/strong\u003e 271 x 225 x 283 mm\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch2\u003eGrundfos STN 3.0 Bar Brass Twin Shower Pump for Negative Head Systems\u003c\/h2\u003e\n\n\u003cp\u003e\u003cstrong\u003eWhat this pump does and who it suits:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe Grundfos STN is a twin impeller shower pump from the Amazon brass range, built to restore strong water pressure in gravity-fed (vented) hot water systems. It is specifically designed for negative head installations, meaning the water level in the cold storage tank sits at or below the level of the shower outlet - a common situation in older Irish homes with a standard cold tank in the attic feeding a hot water cylinder. It is not compatible with combination boilers or unvented pressurised systems.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eTwin impeller regenerative design:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe STN boosts both the hot and cold water feeds simultaneously using two separate impellers, delivering a balanced and consistent flow to the showerhead. The regenerative impeller design gives it a natural ability to handle air pockets in the pipework, which can otherwise cause pump noise or flow interruption with centrifugal types. At 3.0 bar and a maximum flow of 52 litres per minute, it is well suited to supplying a single power shower or multiple outlets around a bathroom.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eBrass construction and build quality:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe pump housing and impellers are machined brass throughout, which provides greater durability and corrosion resistance compared to plastic-bodied alternatives. Silicon carbide shaft seals are fitted as standard to extend service life and reduce wear. Anti-vibration feet are incorporated into the base to minimise transmitted noise and movement during operation, keeping the rated noise level to 55 dB.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eSafety, approvals, and motor protection:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe STN carries WRAS approval (UK Water Regulations Advisory Scheme), confirming it meets full mechanical and water quality standards for use in systems supplying consumable water. The motor includes built-in thermal protection that stops it automatically in the event of overheating, protecting the pump from damage in the event of a dry run or restricted flow. The enclosure is rated IPX2, providing protection against dripping water.\u003c\/p\u003e\n\n\u003cp\u003eShop the \u003ca href=\"\/collections\/all-showers-bathroom-studio\" style=\"color: #2B00FF;\"\u003eAll Showers range\u003c\/a\u003e from Heavins.ie, with delivery available across Ireland.\u003c\/p\u003e\n\n\u003ch3\u003eKey Features\u003c\/h3\u003e\n\u003cstrong\u003eTwin impeller design\u003c\/strong\u003e - boosts hot and cold water simultaneously for balanced shower pressure.\u003cbr\u003e\n\u003cstrong\u003eNegative head rated\u003c\/strong\u003e - correct for systems where the cold tank is at or below shower outlet level.\u003cbr\u003e\n\u003cstrong\u003eBrass housing and impellers\u003c\/strong\u003e - robust construction for long service life in hard-water conditions.\u003cbr\u003e\n\u003cstrong\u003eRegenerative pump type\u003c\/strong\u003e - handles air pockets without flow interruption.\u003cbr\u003e\n\u003cstrong\u003eWRAS approved\u003c\/strong\u003e - cleared for use with drinking water systems (approval no. 1209052).\u003cbr\u003e\n\u003cstrong\u003eSilicon carbide seals\u003c\/strong\u003e - long-life shaft seals reduce wear and operating noise.\u003cbr\u003e\n\u003cstrong\u003eBuilt-in thermal protection\u003c\/strong\u003e - motor stops automatically if it overheats.\u003cbr\u003e\n\u003cstrong\u003eAnti-vibration feet\u003c\/strong\u003e - reduces transmitted noise and movement during operation.\u003cbr\u003e\n\u003cstrong\u003eIPX2 enclosure rating\u003c\/strong\u003e - splash-resistant motor housing.\u003cbr\u003e\n\u003cstrong\u003eContinuously rated\u003c\/strong\u003e - suitable for sustained use in domestic and light commercial applications.\u003cbr\u003e\n\u003cstrong\u003e¾ inch BSP connections\u003c\/strong\u003e - standard UK and Irish pipework fitting size.\u003cbr\u003e\n\u003cstrong\u003eFlow switch included\u003c\/strong\u003e - activates the pump automatically when water flow is detected.\u003cbr\u003e\n\n\u003ch3\u003eSpecifications\u003c\/h3\u003e\n\u003cul\u003e\n\u003cli\u003eModel: Grundfos STN 3.0 (Amazon brass range)\u003c\/li\u003e\n\u003cli\u003ePart number: 98284261\u003c\/li\u003e\n\u003cli\u003ePump type: Twin impeller, regenerative\u003c\/li\u003e\n\u003cli\u003eHead type: Negative head (universal)\u003c\/li\u003e\n\u003cli\u003ePressure rating: 3.0 bar\u003c\/li\u003e\n\u003cli\u003eMaximum head: 30 m\u003c\/li\u003e\n\u003cli\u003eRated head: 24.4 m\u003c\/li\u003e\n\u003cli\u003eClosed valve pressure: 3.4 bar\u003c\/li\u003e\n\u003cli\u003eMinimum static head: 1 m\u003c\/li\u003e\n\u003cli\u003eMaximum flow rate: 52 litres\/min (0.6 m³\/h rated)\u003c\/li\u003e\n\u003cli\u003eInput power (P1 max): 710W\u003c\/li\u003e\n\u003cli\u003eVoltage: 230V, 50Hz, single phase\u003c\/li\u003e\n\u003cli\u003eRated current: 3.1A\u003c\/li\u003e\n\u003cli\u003eFuse rating: 5A\u003c\/li\u003e\n\u003cli\u003eCable length: 1.5 m (no plug fitted - hardwired installation)\u003c\/li\u003e\n\u003cli\u003eMotor type: Induction, continuously rated\u003c\/li\u003e\n\u003cli\u003eInsulation class: F\u003c\/li\u003e\n\u003cli\u003eEnclosure rating: IPX2\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\u003eInlet\/outlet connections: ¾ inch BSP (G)\u003c\/li\u003e\n\u003cli\u003eMinimum pipe size: 22mm\u003c\/li\u003e\n\u003cli\u003eHousing and impeller material: Brass\u003c\/li\u003e\n\u003cli\u003eShaft seal: Silicon carbide (GBQP)\u003c\/li\u003e\n\u003cli\u003eFlow switch: Yes\u003c\/li\u003e\n\u003cli\u003eNoise level: 55 dB\u003c\/li\u003e\n\u003cli\u003eWRAS approval: Yes (approval no. 1209052)\u003c\/li\u003e\n\u003cli\u003eCountry of origin: GB\u003c\/li\u003e\n\u003cli\u003eDimensions (LxWxH): 271 x 225 x 283 mm\u003c\/li\u003e\n\u003cli\u003eWeight: 10.3 kg (net)\u003c\/li\u003e\n\u003cli\u003eManufacturer warranty: 5 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\u003e1 x Grundfos STN 3.0 bar twin impeller shower pump\u003c\/li\u003e\n\u003cli\u003e4 x genuine Grundfos push-fit 22mm flexible connection hoses with filter washers\u003c\/li\u003e\n\u003cli\u003eUser manual\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eSetup and Care\u003c\/h3\u003e\n\u003cp\u003e\u003cstrong\u003eInstallation requirements:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThis pump is designed for hardwired mains connection and requires installation by a qualified plumber or electrician. It is suitable for gravity-fed (vented) hot water systems only and must not be used with combination boilers or unvented pressurised cylinders. Connections are ¾ inch BSP, compatible with 22mm pipework.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003ePositioning and siting:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eThe pump should be installed in a dry, ventilated location such as an airing cupboard, and must be positioned so that the cold storage tank outlet is correctly related to the pump inlet for negative head operation. Anti-vibration feet are fitted to reduce noise transmission through floors or shelving. The IPX2 rating provides basic splash protection but the pump should not be exposed to direct water spray.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eRoutine checks:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003ePeriodic inspection of the flexible connection hoses and filter washers is recommended to maintain flow performance. The pump housing and connections should be checked for signs of moisture or mineral build-up, particularly in hard-water areas. Silicon carbide seals are long-life components and do not require routine replacement under normal use.\u003c\/p\u003e\n\n\u003cp\u003e\u003cstrong\u003eCompatibility and system check:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003eBefore installation, confirm the existing system is gravity-fed and vented, and that the cold storage tank is correctly positioned relative to the shower outlet. The minimum static head requirement is 1 metre. If in doubt about system compatibility, consult a qualified plumber prior to ordering.\u003c\/p\u003e","brand":"Grundfos","offers":[{"title":"Default Title","offer_id":57724908896629,"sku":"5700311402597","price":699.0,"currency_code":"EUR","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0614\/5261\/5816\/files\/heavins-grundfos-stn-3-0-bar-brass-negative-twin-impeller-shower-pump-98284261-01.jpg?v=1793810695","url":"https:\/\/www.heavins.ie\/products\/grundfos-stn-3-0-bar-brass-negative-twin-impeller-shower-pump-98284261","provider":"Heavins","version":"1.0","type":"link"}