{"product_id":"vaillant-40l-stackable-buffer-for-standard-pure-and-standard-plus-cylinders","title":"Vaillant 40l Stackable Buffer for Standard Pure and Standard Plus Cylinders","description":"\u003cdiv style=\"font-size:16px; max-width:900px; font-family:Arial, Helvetica, sans-serif; color:#222222; line-height:1.6;\"\u003e\n\u003cp\u003eThe \u003cstrong\u003eVaillant 40 Litre Stackable Buffer (VP R 40\/5 PPS)\u003c\/strong\u003e is a purpose-built accessory for the \u003cstrong\u003euniSTOR pure and uniSTOR plus standard diameter cylinder range\u003c\/strong\u003e, designed to be installed either above or below the cylinder as part of a heat pump system. Adding 40 litres of open system volume, this compact buffer provides \u003cstrong\u003ehydraulic separation\u003c\/strong\u003e, stores additional heating capacity for use at peak demand, and helps de-ice the evaporator without relying on back-up heating – all while adding only \u003cstrong\u003e415mm\u003c\/strong\u003e to the overall installed height.\u003c\/p\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; gap:10px; margin:20px 0;\"\u003e\n\u003cdiv style=\"flex:1; min-width:130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:700; line-height:1.2;\"\u003e40L\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; margin-top:4px; opacity:0.9;\"\u003eNominal Capacity\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:700; line-height:1.2;\"\u003e415mm\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; margin-top:4px; opacity:0.9;\"\u003eHeight, Insulated\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:700; line-height:1.2;\"\u003e580mm\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; margin-top:4px; opacity:0.9;\"\u003eOuter Diameter, Insulated\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:700; line-height:1.2;\"\u003e16kg\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; margin-top:4px; opacity:0.9;\"\u003eNet Weight\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:700; line-height:1.2;\"\u003e3 bar\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; margin-top:4px; opacity:0.9;\"\u003eMax Operating Pressure\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:130px; background:#008377CF; color:#ffffff; border-radius:8px; padding:14px 10px; text-align:center;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:700; line-height:1.2;\"\u003e85°C\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; margin-top:4px; opacity:0.9;\"\u003eMax Operating Temperature\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"border-left:4px solid #008377CF; background:#E6F6F5; padding:12px 16px; margin:16px 0; border-radius:4px;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:4px;\"\u003eStackable Above or Below the Cylinder\u003c\/div\u003e\n\u003cdiv style=\"color:#333333;\"\u003eThe buffer's compact design allows it to sit either above or below a compatible uniSTOR pure or uniSTOR plus standard diameter cylinder, maximising space efficiency without increasing the system's overall footprint.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border-left:4px solid #946200; background:#FFF4DE; padding:12px 16px; margin:16px 0; border-radius:4px;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#946200; margin-bottom:4px;\"\u003eStandard Diameter Range Only\u003c\/div\u003e\n\u003cdiv style=\"color:#333333;\"\u003eThis 40L buffer (VP R 40\/5 PPS) is sized for the \u003cstrong\u003euniSTOR pure and uniSTOR plus standard diameter cylinders\u003c\/strong\u003e (150–300L). For the slimline cylinder range, use the \u003cstrong\u003e30L buffer (VP R 30\/5 SLPPS, 8000011534)\u003c\/strong\u003e instead – the two are not interchangeable due to differing outer diameters.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"border-left:4px solid #008377CF; background:#E6F6F5; padding:12px 16px; margin:16px 0; border-radius:4px;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:4px;\"\u003eHydraulic Decoupling \u0026amp; Peak Demand Support\u003c\/div\u003e\n\u003cdiv style=\"color:#333333;\"\u003eAs well as adding open system volume, the buffer provides hydraulic decoupling between the heat pump and heating circuit, storing heating capacity to smooth out peak demand and supporting evaporator de-icing without requiring back-up electric heating.\u003c\/div\u003e\n\u003c\/div\u003e\n\n\u003cdiv style=\"display:flex; flex-wrap:wrap; gap:12px; margin:20px 0;\"\u003e\n\u003cdiv style=\"flex:1; min-width:250px; border:1px solid #e0e0e0; border-radius:8px; padding:16px;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eMaximises Peak Efficiency\u003c\/div\u003e\n\u003cdiv style=\"color:#333333; font-size:14px; line-height:1.5;\"\u003eThe additional 40 litres of open system volume helps heat pumps run at their peak efficiency, reducing short-cycling and supporting more stable operation.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:250px; border:1px solid #e0e0e0; border-radius:8px; padding:16px;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eDe-Ices the Evaporator Without Back-Up Heat\u003c\/div\u003e\n\u003cdiv style=\"color:#333333; font-size:14px; line-height:1.5;\"\u003eStored heating capacity in the buffer can be used to de-ice the evaporator during defrost cycles, removing the need for an electric back-up heater to perform this function.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:250px; border:1px solid #e0e0e0; border-radius:8px; padding:16px;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eCompact Stackable Footprint\u003c\/div\u003e\n\u003cdiv style=\"color:#333333; font-size:14px; line-height:1.5;\"\u003eMatching the diameter of the standard uniSTOR range and adding only 415mm to the installed height, the buffer is designed to maximise space efficiency within the customer's home.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:250px; border:1px solid #e0e0e0; border-radius:8px; padding:16px;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eLow-GWP Insulation\u003c\/div\u003e\n\u003cdiv style=\"color:#333333; font-size:14px; line-height:1.5;\"\u003eInsulated with polyurethane foam using a low Global Warming Potential propellant (GWP \u0026lt;5), keeping standby energy consumption to under 0.556 kWh per 24 hours.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:250px; border:1px solid #e0e0e0; border-radius:8px; padding:16px;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eSteel Construction\u003c\/div\u003e\n\u003cdiv style=\"color:#333333; font-size:14px; line-height:1.5;\"\u003eThe cylinder body and connections are manufactured from steel, sized to handle a maximum operating pressure of 3 bar and a maximum operating temperature of 85°C.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1; min-width:250px; border:1px solid #e0e0e0; border-radius:8px; padding:16px;\"\u003e\n\u003cdiv style=\"font-weight:700; color:#008377CF; margin-bottom:6px;\"\u003eSimple 1-Inch Connections\u003c\/div\u003e\n\u003cdiv style=\"color:#333333; font-size:14px; line-height:1.5;\"\u003eWater connections are sized at 1 inch diameter, simplifying integration into the wider heat pump and cylinder pipework.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cp\u003e\u003cstrong\u003eTechnical Specification\u003c\/strong\u003e\u003c\/p\u003e\n\u003ctable style=\"width:100%; border-collapse:collapse; margin:20px 0; font-size:14px;\"\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:8px 12px;\"\u003eProduct Identification\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eProduct Code\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e8000011528\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eProduct Code 2 (Model)\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003eVP R 40\/5 PPS\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eCompatible Cylinder Range\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003euniSTOR pure \u0026amp; uniSTOR plus, standard diameter (150–300L)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:8px 12px;\"\u003eCapacity \u0026amp; Dimensions\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eNominal Capacity\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e40L\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eOuter Diameter, Without Insulation\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e450mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eOuter Diameter, With Insulation\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e580mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eHeight, Without Insulation\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e329mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eHeight, With Insulation\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e415mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eNet Weight\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e16kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eTotal Weight (packed)\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e56kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:8px 12px;\"\u003eConstruction \u0026amp; Materials\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eCylinder \u0026amp; Connection Material\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003eSteel\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eHeat Insulation Material\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003ePolyurethane\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eInsulation Propellant GWP\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e\u0026lt;5\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eWater Connection Diameter\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e1 inch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"background:#008377CF; color:#ffffff; font-weight:700; padding:8px 12px;\"\u003eOperating Parameters\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eMaximum Operating Pressure\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e3 bar\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eMaximum Operating Temperature\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e85°C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003ePressure Loss\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e2.5 kPa\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#f4f4f4;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eMaximum Volume Flow\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e2000 L\/h\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr style=\"background:#ffffff;\"\u003e\n\u003ctd style=\"padding:8px 12px; font-weight:600; width:45%;\"\u003eStandby Energy Consumption\u003c\/td\u003e\n\u003ctd style=\"padding:8px 12px;\"\u003e\u0026lt;0.556 kWh\/24h\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\n\u003cp\u003e\u003cstrong\u003eFrequently Asked Questions\u003c\/strong\u003e\u003c\/p\u003e\n\u003cdiv style=\"margin:20px 0;\"\u003e\n\u003cdetails style=\"margin-bottom:8px; border:1px solid #e0e0e0; border-radius:6px; overflow:hidden;\"\u003e\n\u003csummary style=\"background:#008377CF; color:#ffffff; padding:10px 14px; font-weight:600; cursor:pointer; list-style:none;\"\u003eWhich cylinders is this buffer compatible with?\u003c\/summary\u003e\n\u003cdiv style=\"padding:12px 14px; color:#333333; font-size:14px; line-height:1.5;\"\u003eThe 40L buffer (VP R 40\/5 PPS) is designed for the \u003cstrong\u003euniSTOR pure and uniSTOR plus standard diameter cylinder range\u003c\/strong\u003e (150 to 300 litres), matching their 580mm insulated outer diameter.\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails style=\"margin-bottom:8px; border:1px solid #e0e0e0; border-radius:6px; overflow:hidden;\"\u003e\n\u003csummary style=\"background:#008377CF; color:#ffffff; padding:10px 14px; font-weight:600; cursor:pointer; list-style:none;\"\u003eCan this buffer be installed above the cylinder instead of below?\u003c\/summary\u003e\n\u003cdiv style=\"padding:12px 14px; color:#333333; font-size:14px; line-height:1.5;\"\u003eYes. The buffer is designed to be installed either \u003cstrong\u003eabove or below\u003c\/strong\u003e the cylinder, whichever suits the available space and system layout.\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails style=\"margin-bottom:8px; border:1px solid #e0e0e0; border-radius:6px; overflow:hidden;\"\u003e\n\u003csummary style=\"background:#008377CF; color:#ffffff; padding:10px 14px; font-weight:600; cursor:pointer; list-style:none;\"\u003eWhat is the difference between this and the 30L buffer?\u003c\/summary\u003e\n\u003cdiv style=\"padding:12px 14px; color:#333333; font-size:14px; line-height:1.5;\"\u003eThe 30L buffer (VP R 30\/5 SLPPS, product code 8000011534) is sized for the \u003cstrong\u003eslimline\u003c\/strong\u003e uniSTOR pure and uniSTOR plus cylinders, with a smaller 490mm insulated diameter. The two are not interchangeable – match the buffer to the correct cylinder range.\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails style=\"margin-bottom:8px; border:1px solid #e0e0e0; border-radius:6px; overflow:hidden;\"\u003e\n\u003csummary style=\"background:#008377CF; color:#ffffff; padding:10px 14px; font-weight:600; cursor:pointer; list-style:none;\"\u003eWhat does the buffer do functionally, beyond adding volume?\u003c\/summary\u003e\n\u003cdiv style=\"padding:12px 14px; color:#333333; font-size:14px; line-height:1.5;\"\u003eBeyond the extra 40 litres of open system volume, the buffer provides \u003cstrong\u003ehydraulic decoupling\u003c\/strong\u003e between the heat pump and heating circuit, stores heat for peak demand periods, and supports evaporator de-icing without needing back-up electric heating.\u003c\/div\u003e\n\u003c\/details\u003e\n\u003cdetails style=\"margin-bottom:8px; border:1px solid #e0e0e0; border-radius:6px; overflow:hidden;\"\u003e\n\u003csummary style=\"background:#008377CF; color:#ffffff; padding:10px 14px; font-weight:600; cursor:pointer; list-style:none;\"\u003eHow much height does the buffer add to the installation?\u003c\/summary\u003e\n\u003cdiv style=\"padding:12px 14px; color:#333333; font-size:14px; line-height:1.5;\"\u003eWith insulation fitted, the buffer adds \u003cstrong\u003e415mm\u003c\/strong\u003e to the overall installed height when stacked with a compatible cylinder.\u003c\/div\u003e\n\u003c\/details\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Vaillant","offers":[{"title":"Default Title","offer_id":65281660551517,"sku":"8000011528","price":475.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/VaillantStackableBufferforStandardPureandStandardPlusCylinders.jpg?v=1784297347","url":"https:\/\/qualityheating.co.uk\/products\/vaillant-40l-stackable-buffer-for-standard-pure-and-standard-plus-cylinders","provider":"AIZO Quality Heating","version":"1.0","type":"link"}