{"product_id":"oso-acc450-superstream-450l-cold-water-accumulator-tank","title":"OSO Acc450 SuperStream 450L 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\"\u003e11007355\u003c\/span\u003e\n    \u003cspan class=\"dw-badge navy\"\u003eAcc450\u003c\/span\u003e\n    \u003cspan class=\"dw-badge teal\"\u003eSuperStream\u003c\/span\u003e\n    \u003cspan class=\"dw-badge green\"\u003e450 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 Acc450 SuperStream 450 L Accumulator\u003c\/strong\u003e — Largest power-free cold water booster in the SuperStream range with patented CAD2 diaphragm | Up to ~80 l\/min extra flow | Silent, zero-energy, zero-maintenance | ~225 L usable volume | Vertical install only | WRAS-approved butyl membrane | 5-year warranty | Designed for very large homes, guest houses, small hotels or commercial applications\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-comp-box\"\u003e\n    \u003cstrong style=\"color:#856404\"\u003e✅ The ultimate high-capacity solution – maximum reserve for the most demanding installations\u003c\/strong\u003e\n    \u003cp style=\"margin:0.3rem 0 0;color:#5a3a00\"\u003eProvides the longest possible sustained high-flow period before relying on incoming mains. Ideal when 5+ outlets or heavy simultaneous use is common. No electricity, no noise, no servicing. Scalable with multiple units for even larger systems.\u003c\/p\u003e\n  \u003c\/div\u003e\n\n  \u003cp\u003eThe OSO SuperStream Acc450 is the flagship model in the SuperStream accumulator family — engineered specifically for properties or light commercial sites with extreme simultaneous demand (large family homes, multiple occupancy buildings, small hotels, care facilities, or offices with many bathrooms and appliances). With an impressive 450 litres total volume and approximately 225 litres of usable stored water (at 1.5 bar differential), it delivers the longest buffer of boosted performance, ensuring powerful, consistent pressure across the entire system even during peak usage.\u003c\/p\u003e\n\n  \u003cp\u003eLike the entire SuperStream range, it operates entirely on incoming mains pressure via the patented CAD2 (Controlled Action Diaphragm 2) system — silently supplementing flow by up to ~80 litres per minute with absolutely no electricity, no moving parts, no noise and no maintenance requirements throughout its 5-year warranty period and beyond. The heavy-duty composite fiberglass\/epoxy shell is exceptionally corrosion-resistant, weighs only 46 kg empty (still far lighter than equivalent steel vessels), and is built for long-term reliability in high-demand environments.\u003c\/p\u003e\n\n  \u003cp\u003eThis model is vertical-mount only (no horizontal cradle available), making it suited to taller dedicated spaces such as plant rooms, garages, basements or utility cupboards. It requires no annual servicing and continues to boost performance flawlessly during power cuts — a true “install once and forget” solution for maximum reliability.\u003c\/p\u003e\n\n  \u003ch2\u003eWhat Makes the SuperStream Acc450 Special?\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003e\n\u003cstrong\u003eMaximum Reserve Capacity\u003c\/strong\u003e — ~225 L usable volume — the longest high-flow sustainment of any SuperStream model.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCompletely Passive \u0026amp; Cost-Free\u003c\/strong\u003e — Zero electricity, zero running costs, zero CO₂ — the greenest way to achieve powerful flow.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003ePatented CAD2 Diaphragm\u003c\/strong\u003e — Prevents waterlogging, delivers stable pressure, maximises effective storage.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eUltra-Resilient Composite\u003c\/strong\u003e — Fibreglass\/epoxy shell resists corrosion indefinitely — lighter and more durable than steel.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eCommercial-Grade Scalability\u003c\/strong\u003e — Easily parallel multiple units for hotels, care homes, multi-let properties or larger sites.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eWRAS Hygienic Approval\u003c\/strong\u003e — Butyl membrane (WRAS 1501305) fully safe for potable\/drinking water systems.\u003c\/li\u003e\n    \u003cli\u003e\n\u003cstrong\u003eAbsolute Silence\u003c\/strong\u003e — 0 dB operation — perfect for residential or noise-sensitive commercial environments.\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\u003eExtra-Large Boost\u003c\/strong\u003eUp to ~80 l\/min extra flow — supports 5+ simultaneous high-demand outlets.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eZero Energy \u0026amp; Zero Noise\u003c\/strong\u003ePassive system — 0 W, 0 dB, reliable during outages.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eHighest Usable Volume\u003c\/strong\u003e~225 L effective storage — maximum sustained performance.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eWRAS-Approved Membrane\u003c\/strong\u003eButyl rubber (ref 1501305) — hygienic \u0026amp; potable-safe.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eComposite Construction\u003c\/strong\u003eLightweight (46 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 for peak efficiency.\u003c\/div\u003e\n    \u003cdiv class=\"dw-card\"\u003e\n\u003cstrong\u003eHighly Scalable\u003c\/strong\u003eParallel multiple units with add-on kits for commercial-scale demand.\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\u003e11007355\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eTotal Vessel Volume\u003c\/td\u003e\n\u003ctd\u003e450 litres\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eUsable Water Volume\u003c\/td\u003e\n\u003ctd\u003e~225 litres (at 1.5 bar differential)\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eDimensions (Ø × Height – vertical only)\u003c\/td\u003e\n\u003ctd\u003e614 × 1831 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eEmpty Weight\u003c\/td\u003e\n\u003ctd\u003e46 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003ctd\u003eFull Weight (approx.)\u003c\/td\u003e\n\u003ctd\u003e271 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 × Acc450 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✔ Pre-charge adjustment \u0026amp; vertical mounting guide\u003c\/div\u003e\n    \u003cdiv class=\"dw-contents-item\"\u003e✔ Full installation \u0026amp; commissioning 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. For very low incoming pressure add Charger Pump (11007348). Vertical mount only — no horizontal cradle available for this model.\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 the Acc450 require electricity or servicing?\u003c\/strong\u003e\n    No — completely passive, silent (0 dB), zero power draw and zero maintenance for 5+ years.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eHow much additional flow does it provide?\u003c\/strong\u003e\n    Supplements incoming mains by up to ~80 litres per minute — excellent for 5+ simultaneous high-flow outlets without pressure drop.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eCan it be installed horizontally?\u003c\/strong\u003e\n    No — vertical installation only. For horizontal mounting choose Acc200 or Acc250 with cradle.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eIs it suitable for drinking water systems?\u003c\/strong\u003e\n    Yes — WRAS-approved butyl membrane (ref 1501305) ensures safe, hygienic storage of potable water.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eCan multiple Acc450 units be connected?\u003c\/strong\u003e\n    Yes — parallel setup is simple and highly effective. One Upstream Kit for the first unit + Add-on Kits for each additional accumulator.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eWill it improve performance of unvented cylinders or combi boilers?\u003c\/strong\u003e\n    Yes — significantly enhances hot \u0026amp; cold delivery on weak or restricted mains supplies, improving recovery and pressure.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eWhat if incoming mains pressure is extremely low?\u003c\/strong\u003e\n    For dynamic pressure consistently below ~2 bar, pair with the SuperStream Charger Pump (11007348) to pre-boost supply before the accumulator.\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 construction is highly corrosion-resistant and much lighter\/stronger than traditional steel vessels.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eDoes the air pre-charge need frequent adjustment?\u003c\/strong\u003e\n    Factory-set at 1.4 bar and sealed for the vessel life; occasional checks are simple but rarely required.\n  \u003c\/div\u003e\n\n  \u003cdiv class=\"dw-faq-item\"\u003e\n    \u003cstrong\u003eIs this suitable for commercial use?\u003c\/strong\u003e\n    Yes — ideal for small hotels, care homes, multi-occupancy buildings or light commercial where high simultaneous demand occurs regularly.\n  \u003c\/div\u003e\n\n\u003c\/div\u003e","brand":"OSO Hotwater","offers":[{"title":"Default Title","offer_id":63734035087709,"sku":"Acc450","price":1630.0,"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-acc450-superstream-450l-cold-water-accumulator-tank","provider":"AIZO Quality Heating","version":"1.0","type":"link"}