{"product_id":"oso-acc250-superstream-250l-cold-water-accumulator-tank","title":"OSO Acc250 SuperStream 250L Cold Water Accumulator Tank","description":"\u003cstyle\u003e\n  .dw-wrap{font-family:inherit;color:inherit;line-height:1.7;font-size:16px}\n  .dw-wrap p,.dw-wrap li,.dw-wrap td,.dw-wrap th{font-size:16px!important;line-height:1.7}\n  .dw-wrap h2{font-size:22px!important;font-weight:700;color:#1a3a5c;border-bottom:3px solid #008377;padding-bottom:6px;margin:2rem 0 1rem;line-height:1.3}\n  .dw-wrap h3{font-size:17px!important;font-weight:700;color:#1a3a5c;margin:1.2rem 0 0.4rem;line-height:1.4}\n  .dw-wrap p{margin:0 0 1rem}\n  .dw-wrap ul{padding-left:1.5rem;margin:0 0 1rem}\n  .dw-wrap ul li{margin-bottom:0.5rem}\n  .dw-badge{display:inline-block;font-size:13px!important;font-weight:700;border-radius:4px;padding:2px 10px;margin-right:5px;margin-bottom:4px;vertical-align:middle}\n  .dw-badge.blue{background:#008377;color:#fff}\n  .dw-badge.navy{background:#1a3a5c;color:#fff}\n  .dw-badge.teal{background:#0d9488;color:#fff}\n  .dw-badge.green{background:#1a7a3c;color:#fff}\n  .dw-badge.grey{background:#555;color:#fff}\n  .dw-intro-box{background:#e0f2fe;border-left:4px solid #008377CF;padding:1.1rem 1.4rem;border-radius:0 6px 6px 0;margin-bottom:1.5rem}\n  .dw-intro-box p{margin:0!important}\n  .dw-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:0.85rem;margin-bottom:1.2rem}\n  .dw-card{background:#e0f2fe;border:1px solid #90caf9;border-radius:6px;padding:1rem 1.1rem;line-height:1.6}\n  .dw-card strong{display:block;color:#1a3a5c;margin-bottom:0.35rem;font-size:16px!important}\n  .dw-info-box{background:#f0fdf4;border:1px solid #86efac;border-radius:6px;padding:1rem 1.2rem;margin:1.2rem 0}\n  .dw-info-box p{margin:0 0 0.5rem!important;color:#065f46;font-weight:700}\n  .dw-comp-box{background:#fff3cd;border:1px solid #ffc107;border-radius:5px;padding:0.9rem 1.1rem;margin:0.8rem 0}\n  .dw-spec-table{width:100%;border-collapse:collapse;margin-bottom:1.5rem}\n  .dw-spec-table th{background:#1a3a5c;color:#fff!important;text-align:left;padding:0.7rem 1rem;font-weight:700;font-size:16px!important}\n  .dw-spec-table td{padding:0.6rem 1rem;border-bottom:1px solid #bde0f5;vertical-align:top;font-size:16px!important}\n  .dw-spec-table tr:nth-child(even) td{background:#e0f2fe}\n  .dw-spec-table td:first-child{font-weight:600;color:#111;width:44%}\n  .dw-faq-item{border-bottom:1px solid #bde0f5;padding:0.9rem 0}\n  .dw-faq-item:last-child{border-bottom:none}\n  .dw-faq-item strong{color:#1a3a5c;font-size:16px!important;display:block;margin-bottom:0.3rem}\n  .dw-contents-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:0.6rem;margin-bottom:1.2rem}\n  .dw-contents-item{background:#f0f9ff;border:1px solid #bde0f5;border-radius:5px;padding:0.6rem 0.9rem;font-size:15px!important}\n\u003c\/style\u003e\n\n\u003cdiv class=\"dw-wrap\"\u003e\n\n  \u003cdiv style=\"margin-bottom:1rem\"\u003e\n    \u003cspan class=\"dw-badge blue\"\u003e11007352\u003c\/span\u003e\n    \u003cspan class=\"dw-badge navy\"\u003eAcc250\u003c\/span\u003e\n    \u003cspan class=\"dw-badge teal\"\u003eSuperStream\u003c\/span\u003e\n    \u003cspan class=\"dw-badge green\"\u003e250 L\u003c\/span\u003e\n    \u003cspan class=\"dw-badge grey\"\u003eCold Water Accumulator\u003c\/span\u003e\n    \u003cspan class=\"dw-badge grey\"\u003ePower-Free Booster\u003c\/span\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-intro-box\"\u003e\n    \u003cp\u003e\u003cstrong\u003eOSO Acc250 SuperStream 250 L Accumulator\u003c\/strong\u003e — High-capacity power-free cold water booster with patented CAD2 diaphragm | Up to ~80 l\/min extra flow | Silent, zero-energy, zero-maintenance | ~125 L usable volume | Horizontal or vertical install (cradle required for horizontal) | WRAS-approved butyl membrane | 5-year warranty | Ideal for 3+ bathroom homes or light commercial\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-comp-box\"\u003e\n    \u003cstrong style=\"color:#856404\"\u003e✅ Largest practical home size in the range – perfect for demanding households or small commercial\u003c\/strong\u003e\n    \u003cp style=\"margin:0.3rem 0 0;color:#5a3a00\"\u003eDelivers extended high-flow periods for multiple showers, baths, kitchen \u0026amp; utility use simultaneously. No electricity, no noise, no servicing. Expandable with add-on kits for even greater capacity.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cp\u003eThe OSO SuperStream Acc250 is the largest vertical\/horizontal accumulator designed for residential and light commercial applications where very high simultaneous demand is expected — think large family homes, guest houses, or small offices with multiple bathrooms and appliances. With 250 litres total volume and approximately 125 litres of usable stored water (at 1.5 bar differential), it provides significantly longer periods of boosted flow before falling back to incoming mains performance.\u003c\/p\u003e\n\n  \u003cp\u003ePowered entirely by incoming mains pressure and the patented CAD2 diaphragm system, it silently supplements flow by up to ~80 litres per minute with zero electricity, zero noise and zero maintenance requirements. The composite fiberglass\/epoxy construction is lightweight (27 kg empty), corrosion-proof and far more durable than traditional steel vessels. A standout feature is the ability to mount horizontally using the dedicated Horizontal Cradle (11007329), making it ideal for space-constrained lofts, plant rooms or under-stair cupboards.\u003c\/p\u003e\n\n  \u003ch2\u003eWhat Makes the SuperStream Acc250 Special?\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eHighest Home Capacity\u003c\/strong\u003e — ~125 L usable reserve — longest high-flow duration in the domestic SuperStream range.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCompletely Passive \u0026amp; Green\u003c\/strong\u003e — No power, no CO₂, no bills — sustainable boosting that works during power cuts.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePatented CAD2 Technology\u003c\/strong\u003e — Prevents waterlogging, ensures consistent pressure delivery, maximises effective volume.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eHorizontal or Vertical Flexibility\u003c\/strong\u003e — Horizontal option (with cradle) saves valuable vertical space in tight installations.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eUltra-Durable Composite\u003c\/strong\u003e — Fibreglass\/epoxy shell resists corrosion indefinitely — lighter and stronger than steel.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eScalable to Commercial Levels\u003c\/strong\u003e — Parallel multiple units easily for hotels, care homes or multi-let properties.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWRAS Hygienic Approval\u003c\/strong\u003e — Butyl membrane (WRAS 1501305) safe for drinking water systems.\u003c\/li\u003e\n  \u003c\/ul\u003e\n\n  \u003ch2\u003eKey Features\u003c\/h2\u003e\n  \u003cdiv class=\"dw-grid\"\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eExtended Flow Boost\u003c\/strong\u003eUp to ~80 l\/min extra — supports 3+ simultaneous high-demand outlets.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eZero Energy \u0026amp; Silent\u003c\/strong\u003ePassive system — 0 W, 0 dB, reliable in blackouts.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eHigh Usable Volume\u003c\/strong\u003e~125 L effective storage — longer powerful performance.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eHorizontal Mounting\u003c\/strong\u003eSupported with Cradle (11007329) for low-height spaces.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eWRAS-Approved Membrane\u003c\/strong\u003eButyl rubber (ref 1501305) — safe \u0026amp; hygienic.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eComposite Shell\u003c\/strong\u003eLightweight (27 kg empty), corrosion-proof, 5-year warranty.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eAdjustable Pre-Charge\u003c\/strong\u003e1.4 bar factory — optimise on site.\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n  \u003ctable class=\"dw-spec-table\"\u003e\n    \u003ctr\u003e\n\u003cth\u003eSpecification\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e11007352\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTotal Vessel Volume\u003c\/td\u003e\n\u003ctd\u003e250 litres\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eUsable Water Volume\u003c\/td\u003e\n\u003ctd\u003e~125 litres (at 1.5 bar differential)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDimensions (Ø × Height – vertical)\u003c\/td\u003e\n\u003ctd\u003e542 × 1303 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eEmpty Weight\u003c\/td\u003e\n\u003ctd\u003e27 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eFull Weight (approx.)\u003c\/td\u003e\n\u003ctd\u003e152 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eConnections\u003c\/td\u003e\n\u003ctd\u003e1¼\" BSP male × 28 mm compression\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMax Working Pressure\u003c\/td\u003e\n\u003ctd\u003e8.6 bar (860 kPa)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003ePre-charge Pressure\u003c\/td\u003e\n\u003ctd\u003e1.4 bar (factory — adjustable)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMax Boost Head (closed valve)\u003c\/td\u003e\n\u003ctd\u003e4.3 bar\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eWater Temperature Range\u003c\/td\u003e\n\u003ctd\u003e4 °C to 35 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eAmbient Temperature Max\u003c\/td\u003e\n\u003ctd\u003e40 °C\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eMembrane Material\u003c\/td\u003e\n\u003ctd\u003eButyl rubber (WRAS 1501305)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTank Construction\u003c\/td\u003e\n\u003ctd\u003eContinuous strand fibreglass + epoxy resin\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eWarranty\u003c\/td\u003e\n\u003ctd\u003e5 years (vessel \u0026amp; diaphragm)\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/table\u003e\n\n  \u003ch2\u003eWhat's in the Box\u003c\/h2\u003e\n  \u003cdiv class=\"dw-contents-grid\"\u003e\n    \u003cdiv class=\"dw-contents-item\"\u003e✔ 1 × Acc250 SuperStream Accumulator Vessel\u003c\/div\u003e\n    \u003cdiv class=\"dw-contents-item\"\u003e✔ 1¼\" BSP male to 28 mm compression fittings\u003c\/div\u003e\n    \u003cdiv class=\"dw-contents-item\"\u003e✔ Orientation \u0026amp; pre-charge guide\u003c\/div\u003e\n    \u003cdiv class=\"dw-contents-item\"\u003e✔ Full installation manual\u003c\/div\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-info-box\"\u003e\n    \u003cp\u003e✅ Required accessories: Upstream Kit 22\/28 mm (11007380) for first unit + Add-on Kit (11007327) per extra accumulator. Horizontal install needs Horizontal Cradle (11007329). Low pressure? Add Charger Pump (11007348).\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eDoes it use electricity or need servicing?\u003c\/strong\u003e\n    No — fully passive, silent, zero power and zero maintenance for 5+ years.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eHow much boost can I expect?\u003c\/strong\u003e\n    Up to ~80 l\/min extra flow — excellent for 3+ simultaneous outlets (showers, baths, kitchen) without pressure drop.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eIs horizontal mounting possible?\u003c\/strong\u003e\n    Yes — use the Horizontal Cradle (11007329) to install horizontally in lofts or tight spaces.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eIs it drinking water safe?\u003c\/strong\u003e\n    Yes — WRAS-approved butyl membrane (1501305) stores clean potable water.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eCan I link multiple Acc250 units?\u003c\/strong\u003e\n    Yes — parallel connection is simple. One Upstream Kit + Add-on Kits for each additional unit.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eWill it improve my unvented cylinder or combi?\u003c\/strong\u003e\n    Yes — dramatically improves hot \u0026amp; cold delivery on weak mains supplies.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eWhat if pressure is very low?\u003c\/strong\u003e\n    Below ~2 bar dynamic — pair with Charger Pump (11007348) to pre-boost incoming supply.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eHow durable is the composite tank?\u003c\/strong\u003e\n    Extremely — fibreglass\/epoxy resists corrosion far better than steel; lightweight yet very strong.\n  \u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"OSO Hotwater","offers":[{"title":"Default Title","offer_id":63733980299613,"sku":"Acc250","price":1030.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/OSOSuperStreamColdWaterAccumulatorTank.jpg?v=1772780702","url":"https:\/\/qualityheating.co.uk\/products\/oso-acc250-superstream-250l-cold-water-accumulator-tank","provider":"AIZO Quality Heating","version":"1.0","type":"link"}