{"product_id":"viessmann-vitodens-100-w-25kw-b1hf-system-boiler-7988418","title":"Viessmann Vitodens 100-W 25kW B1HF System Boiler | 7988418","description":"\u003c!-- SEO Product Name: Viessmann Vitodens 100-W 25kW B1HF System Boiler | 7988418 --\u003e\n\u003cdiv style=\"font-size:16px; max-width:900px; margin:0 auto; color:#2B2B2B; line-height:1.6; font-family:Arial, Helvetica, sans-serif;\"\u003e\n\u003cp style=\"font-size:16px; line-height:1.7; color:#2B2B2B; margin:0 0 16px 0;\"\u003eThe \u003cstrong\u003eViessmann Vitodens 100-W\u003c\/strong\u003e is the flagship wall-mounted gas condensing boiler in the Vitodens range, pairing the \u003cstrong\u003eMatriX-Plus gas burner\u003c\/strong\u003e with intelligent \u003cstrong\u003eLambda Pro combustion control\u003c\/strong\u003e and the corrosion-resistant Inox-Radial stainless steel heat exchanger.\u003c\/p\u003e\n\u003cp style=\"font-size:16px; line-height:1.7; color:#2B2B2B; margin:0 0 16px 0;\"\u003eThis 25kW system boiler variant heats a separate hot water cylinder, offering a well-balanced output for \u003cstrong\u003emedium-sized homes\u003c\/strong\u003e with moderate heating and hot water demand.\u003c\/p\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; margin:20px -4px 24px -4px;\"\u003e\n\u003cdiv style=\"flex:1 1 140px; min-width:120px; background:#F7FAFA; border:1px solid #D9EDEA; border-top:3px solid #008377CF; border-radius:6px; padding:14px 10px; text-align:center; margin:4px;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:800; color:#00625D;\"\u003e25kW\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; color:#5A5A5A; margin-top:4px; line-height:1.3;\"\u003eSystem output\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 140px; min-width:120px; background:#F7FAFA; border:1px solid #D9EDEA; border-top:3px solid #008377CF; border-radius:6px; padding:14px 10px; text-align:center; margin:4px;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:800; color:#00625D;\"\u003e94%\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; color:#5A5A5A; margin-top:4px; line-height:1.3;\"\u003eSeasonal efficiency (ηS)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 140px; min-width:120px; background:#F7FAFA; border:1px solid #D9EDEA; border-top:3px solid #008377CF; border-radius:6px; padding:14px 10px; text-align:center; margin:4px;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:800; color:#00625D;\"\u003e46 dB(A)\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; color:#5A5A5A; margin-top:4px; line-height:1.3;\"\u003eSound level\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 140px; min-width:120px; background:#F7FAFA; border:1px solid #D9EDEA; border-top:3px solid #008377CF; border-radius:6px; padding:14px 10px; text-align:center; margin:4px;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:800; color:#00625D;\"\u003eClass A\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; color:#5A5A5A; margin-top:4px; line-height:1.3;\"\u003eEnergy efficiency\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 140px; min-width:120px; background:#F7FAFA; border:1px solid #D9EDEA; border-top:3px solid #008377CF; border-radius:6px; padding:14px 10px; text-align:center; margin:4px;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:800; color:#00625D;\"\u003e360mm\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; color:#5A5A5A; margin-top:4px; line-height:1.3;\"\u003eDepth\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 140px; min-width:120px; background:#F7FAFA; border:1px solid #D9EDEA; border-top:3px solid #008377CF; border-radius:6px; padding:14px 10px; text-align:center; margin:4px;\"\u003e\n\u003cdiv style=\"font-size:20px; font-weight:800; color:#00625D;\"\u003e\u003cspan style=\"color:#008377CF;\"\u003eWiFi\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px; color:#5A5A5A; margin-top:4px; line-height:1.3;\"\u003eBuilt-in connectivity\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#FFF6E5; border-left:4px solid #E0942A; border-radius:4px; padding:14px 16px; margin:0 0 20px 0; display:flex; align-items:flex-start; gap:10px;\"\u003e\n\u003cspan style=\"font-size:18px; line-height:1;\"\u003e🛈\u003c\/span\u003e\u003cdiv style=\"font-size:15px; color:#2B2B2B; line-height:1.55;\"\u003e\n\u003cstrong style=\"color:#E0942A;\"\u003ePlease Note:\u003c\/strong\u003e This boiler must be connected using the Viessmann 60\/100mm concentric flue system, tested and CE-designated as one structural unit with the boiler in accordance with DVGW-VP 113. Only this flue system may be used, with maximum flue lengths varying by model — check the installation manual for the exact figure.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#E6F4F3; border-left:4px solid #008377CF; border-radius:4px; padding:14px 16px; margin:0 0 20px 0; display:flex; align-items:flex-start; gap:10px;\"\u003e\n\u003cspan style=\"font-size:18px; line-height:1;\"\u003eℹ\u003c\/span\u003e\u003cdiv style=\"font-size:15px; color:#2B2B2B; line-height:1.55;\"\u003e\n\u003cstrong style=\"color:#008377CF;\"\u003eGood to Know:\u003c\/strong\u003e This boiler is approved for a hydrogen admixture of up to 20% by volume and can be configured for LPG entirely from the control unit — no separate conversion kit is required.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; flex-wrap:wrap; margin:0 -6px 24px -6px;\"\u003e\n\u003cdiv style=\"flex:1 1 260px; min-width:240px; background:#FFFFFF; border:1px solid #D9EDEA; border-radius:8px; padding:16px; margin:6px;\"\u003e\n\u003cdiv style=\"font-size:15.5px; font-weight:700; color:#00625D; margin-bottom:6px;\"\u003eMatriX-Plus burner with Lambda Pro\u003c\/div\u003e\n\u003cdiv style=\"font-size:14.5px; color:#3A3A3A; line-height:1.55;\"\u003eDelivers \u003cstrong\u003eextremely clean combustion\u003c\/strong\u003e and quiet operation, with automatic combustion control across the full modulation range.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; min-width:240px; background:#FFFFFF; border:1px solid #D9EDEA; border-radius:8px; padding:16px; margin:6px;\"\u003e\n\u003cdiv style=\"font-size:15.5px; font-weight:700; color:#00625D; margin-bottom:6px;\"\u003eLow sound power output\u003c\/div\u003e\n\u003cdiv style=\"font-size:14.5px; color:#3A3A3A; line-height:1.55;\"\u003eRated at just \u003cstrong\u003e46 dB(A)\u003c\/strong\u003e at full output, keeping the boiler unobtrusive in living spaces.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; min-width:240px; background:#FFFFFF; border:1px solid #D9EDEA; border-radius:8px; padding:16px; margin:6px;\"\u003e\n\u003cdiv style=\"font-size:15.5px; font-weight:700; color:#00625D; margin-bottom:6px;\"\u003eInox-Radial stainless steel heat exchanger\u003c\/div\u003e\n\u003cdiv style=\"font-size:14.5px; color:#3A3A3A; line-height:1.55;\"\u003eProvides \u003cstrong\u003ehigh operational reliability\u003c\/strong\u003e and a long service life on a compact footprint.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; min-width:240px; background:#FFFFFF; border:1px solid #D9EDEA; border-radius:8px; padding:16px; margin:6px;\"\u003e\n\u003cdiv style=\"font-size:15.5px; font-weight:700; color:#00625D; margin-bottom:6px;\"\u003eVariable speed high efficiency circulation pump\u003c\/div\u003e\n\u003cdiv style=\"font-size:14.5px; color:#3A3A3A; line-height:1.55;\"\u003eCuts pump \u003cstrong\u003epower consumption by up to 70%\u003c\/strong\u003e compared with a fixed-speed equivalent.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; min-width:240px; background:#FFFFFF; border:1px solid #D9EDEA; border-radius:8px; padding:16px; margin:6px;\"\u003e\n\u003cdiv style=\"font-size:15.5px; font-weight:700; color:#00625D; margin-bottom:6px;\"\u003eIntegral WiFi with local app access\u003c\/div\u003e\n\u003cdiv style=\"font-size:14.5px; color:#3A3A3A; line-height:1.55;\"\u003eSupports the \u003cstrong\u003eViCare app\u003c\/strong\u003e for remote control, plus local commissioning access without an active internet connection.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1 1 260px; min-width:240px; background:#FFFFFF; border:1px solid #D9EDEA; border-radius:8px; padding:16px; margin:6px;\"\u003e\n\u003cdiv style=\"font-size:15.5px; font-weight:700; color:#00625D; margin-bottom:6px;\"\u003eTouchscreen control unit\u003c\/div\u003e\n\u003cdiv style=\"font-size:14.5px; color:#3A3A3A; line-height:1.55;\"\u003eEasy day-to-day operation via a \u003cstrong\u003ebacklit LCD touchscreen\u003c\/strong\u003e display.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-size:19px; font-weight:700; color:#00625D; margin:32px 0 14px 0; padding-bottom:8px; border-bottom:2px solid #008377CF;\"\u003eSpecification\u003c\/div\u003e\n\u003cdiv style=\"background:#008377CF; color:#FFFFFF; font-weight:700; font-size:13.5px; letter-spacing:.04em; text-transform:uppercase; padding:9px 14px; border-radius:6px 6px 0 0; margin-top:14px;\"\u003ePerformance\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #D9EDEA; border-top:none; border-radius:0 0 6px 6px; overflow:hidden; margin-bottom:6px;\"\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eBoiler type\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003eGas condensing system boiler (Type B1HF)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eRated heat output (50\/30°C)\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e3.2 – 25.0 kW\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eRated heat output (80\/60°C)\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e2.9 – 23.0 kW\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eContinuous cylinder heating output\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e2.9 – 23.0 kW\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eStandard seasonal efficiency (Hs)\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003eUp to 98%\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eSeasonal central heating efficiency (ηS)\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e94%\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eEnergy efficiency class\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003eA\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eSound power level (rated output)\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e46.1 dB(A)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#008377CF; color:#FFFFFF; font-weight:700; font-size:13.5px; letter-spacing:.04em; text-transform:uppercase; padding:9px 14px; border-radius:6px 6px 0 0; margin-top:14px;\"\u003eGas \u0026amp; Electrical\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #D9EDEA; border-top:none; border-radius:0 0 6px 6px; overflow:hidden; margin-bottom:6px;\"\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eGas types\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003eNatural gas and LPG (configured at control unit)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eHydrogen compatibility\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003eUp to 20% H2 blend\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eNatural gas supply pressure\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e20 mbar\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eLPG supply pressure\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e50 mbar\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eElectrical supply\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e230V~, 50Hz\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003ePower consumption (delivered condition)\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e67W\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#008377CF; color:#FFFFFF; font-weight:700; font-size:13.5px; letter-spacing:.04em; text-transform:uppercase; padding:9px 14px; border-radius:6px 6px 0 0; margin-top:14px;\"\u003eDimensions \u0026amp; Connections\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #D9EDEA; border-top:none; border-radius:0 0 6px 6px; overflow:hidden; margin-bottom:6px;\"\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eHeight\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e700mm\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eWidth\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e400mm\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eDepth\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e360mm\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eWeight (excl. water)\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e32kg\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eFlue gas connection\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e60mm\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eVentilation air connection\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e100mm\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eBoiler flow and return\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003eR 3\/4\"\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eCold water and DHW connections\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003eG 1\/2\"\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#008377CF; color:#FFFFFF; font-weight:700; font-size:13.5px; letter-spacing:.04em; text-transform:uppercase; padding:9px 14px; border-radius:6px 6px 0 0; margin-top:14px;\"\u003eExpansion Vessel\u003c\/div\u003e\n\u003cdiv style=\"border:1px solid #D9EDEA; border-top:none; border-radius:0 0 6px 6px; overflow:hidden; margin-bottom:6px;\"\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eCapacity\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e8 litres\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#F7FAFA; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003ePre-charge pressure\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e0.75 bar\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"display:flex; background:#FFFFFF; border-bottom:1px solid #D9EDEA;\"\u003e\n\u003cdiv style=\"flex:0 0 46%; padding:9px 14px; font-weight:600; font-size:14px; color:#333333;\"\u003eMax. permissible operating pressure\u003c\/div\u003e\n\u003cdiv style=\"flex:1; padding:9px 14px; font-size:14px; color:#222222;\"\u003e3 bar\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdetails style=\"border:1px solid #D9EDEA; border-radius:6px; margin-bottom:8px; overflow:hidden;\"\u003e\u003csummary style=\"padding:13px 16px; font-size:15px; font-weight:700; color:#00625D; cursor:pointer; list-style:none; display:flex; align-items:center; justify-content:space-between; background:#E6F4F3;\"\u003e\u003cspan\u003eWhat cylinder output does this boiler support?\u003c\/span\u003e\u003csvg width=\"16\" height=\"16\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#008377CF\" stroke-width=\"2.5\"\u003e\u003cpolyline points=\"6 9 12 15 18 9\"\u003e\u003c\/polyline\u003e\u003c\/svg\u003e\u003c\/summary\u003e\u003cdiv style=\"padding:13px 16px 15px 16px; font-size:14.5px; color:#3A3A3A; line-height:1.6; border-top:1px solid #D9EDEA; background:#FFFFFF;\"\u003eThe 25kW model supports a continuous cylinder heating output of 2.9 to 23.0 kW, suiting a standard indirect cylinder for a medium-sized home.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #D9EDEA; border-radius:6px; margin-bottom:8px; overflow:hidden;\"\u003e\u003csummary style=\"padding:13px 16px; font-size:15px; font-weight:700; color:#00625D; cursor:pointer; list-style:none; display:flex; align-items:center; justify-content:space-between; background:#E6F4F3;\"\u003e\u003cspan\u003eDoes this boiler require a mounting jig?\u003c\/span\u003e\u003csvg width=\"16\" height=\"16\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#008377CF\" stroke-width=\"2.5\"\u003e\u003cpolyline points=\"6 9 12 15 18 9\"\u003e\u003c\/polyline\u003e\u003c\/svg\u003e\u003c\/summary\u003e\u003cdiv style=\"padding:13px 16px 15px 16px; font-size:14.5px; color:#3A3A3A; line-height:1.6; border-top:1px solid #D9EDEA; background:#FFFFFF;\"\u003eYes, a pre-plumbing jig or valves\/fittings pack for surface or flush mounting must be ordered separately.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #D9EDEA; border-radius:6px; margin-bottom:8px; overflow:hidden;\"\u003e\u003csummary style=\"padding:13px 16px; font-size:15px; font-weight:700; color:#00625D; cursor:pointer; list-style:none; display:flex; align-items:center; justify-content:space-between; background:#E6F4F3;\"\u003e\u003cspan\u003eHow quiet is this boiler in operation?\u003c\/span\u003e\u003csvg width=\"16\" height=\"16\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#008377CF\" stroke-width=\"2.5\"\u003e\u003cpolyline points=\"6 9 12 15 18 9\"\u003e\u003c\/polyline\u003e\u003c\/svg\u003e\u003c\/summary\u003e\u003cdiv style=\"padding:13px 16px 15px 16px; font-size:14.5px; color:#3A3A3A; line-height:1.6; border-top:1px solid #D9EDEA; background:#FFFFFF;\"\u003eAt its rated output the 25kW model has a sound power level of 46.1 dB(A), and drops to 31.9 dB(A) at partial load — among the quietest in its class.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #D9EDEA; border-radius:6px; margin-bottom:8px; overflow:hidden;\"\u003e\u003csummary style=\"padding:13px 16px; font-size:15px; font-weight:700; color:#00625D; cursor:pointer; list-style:none; display:flex; align-items:center; justify-content:space-between; background:#E6F4F3;\"\u003e\u003cspan\u003eCan this boiler be used in a multi-boiler cascade installation?\u003c\/span\u003e\u003csvg width=\"16\" height=\"16\" viewbox=\"0 0 24 24\" fill=\"none\" stroke=\"#008377CF\" stroke-width=\"2.5\"\u003e\u003cpolyline points=\"6 9 12 15 18 9\"\u003e\u003c\/polyline\u003e\u003c\/svg\u003e\u003c\/summary\u003e\u003cdiv style=\"padding:13px 16px 15px 16px; font-size:14.5px; color:#3A3A3A; line-height:1.6; border-top:1px solid #D9EDEA; background:#FFFFFF;\"\u003eYes, a multiple connection variant (B1HF-M) is available for vertical multiple connection or horizontal cascade setups.\u003c\/div\u003e\u003c\/details\u003e\n\u003c\/div\u003e","brand":"Viessmann","offers":[{"title":"Default Title","offer_id":65942110568797,"sku":"7988418","price":1895.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/ViessmannVitodens100-WB1HFSystemBoiler7098715.jpg?v=1789623898","url":"https:\/\/qualityheating.co.uk\/products\/viessmann-vitodens-100-w-25kw-b1hf-system-boiler-7988418","provider":"AIZO Quality Heating","version":"1.0","type":"link"}