{"product_id":"holzvergaserkessel-defro-optima-hg-25-kw","title":"Wood Gasification Boiler Defro Optima HG 25 kW","description":"\u003cdiv class=\"gema-section\"\u003e \u003ch2\u003eProduct Overview \u0026 Application\u003c\/h2\u003e \u003cp\u003eThe Defro Optima HG 25 kW wood gasification boiler is a manually fed central heating boiler designed for split logs and use in water-based heating systems. It is suitable for installations where firewood is used as fuel and the generated heat is integrated into the heating system via a buffer tank.\u003c\/p\u003e \u003cp\u003eThe boiler is intended for closed hot water heating systems and operates with a maximum flow temperature of 90 °C. The 25 kW output makes it a suitable solution for appropriately designed wood heating systems, although the specific boiler selection should always be based on the heat load and system design.\u003c\/p\u003e \u003c\/div\u003e \u003cdiv class=\"gema-section\"\u003e \u003ch2\u003eTechnology \u0026 Equipment\u003c\/h2\u003e \u003cp\u003eThe Optima HG operates on the wood gasification principle. The split logs are degassed in the upper combustion chamber; the wood gases are directed through the combustion nozzle into the lower combustion chamber where they are burned off. Heat transfer occurs via the boiler body with a water jacket and the tube heat exchangers.\u003c\/p\u003e \u003cp\u003eEquipment includes an electronic control unit, an induced draft fan, fireclay bricks in the combustion chambers, a combustion nozzle, turbulators, and a cleaning mechanism for the heat exchangers. A safety temperature limiter cuts the power supply to the fan if the boiler temperature exceeds the specified limit range.\u003c\/p\u003e \u003c\/div\u003e \u003cdiv class=\"gema-section\"\u003e \u003ch2\u003eEveryday Advantages\u003c\/h2\u003e \u003cp\u003eThe wide filling door makes it easier to load split logs, while the separate arrangement of the filling, combustion chamber, and ash doors facilitates access for cleaning and maintenance. The sight glass allows visual inspection of the gasification flame without unnecessarily interrupting the combustion process.\u003c\/p\u003e \u003cp\u003eThrough the intended operation with a buffer tank, the generated heat can be stored temporarily and released to the heating system as needed. This supports smooth system operation and helps integrate the heat from log burning effectively into the overall system.\u003c\/p\u003e \u003c\/div\u003e \u003cdiv class=\"gema-section\"\u003e \u003ch2\u003eSystem Integration \u0026 Compatibility\u003c\/h2\u003e \u003cp\u003eThe Defro Optima HG 25 kW is designed for integration into closed heating systems according to DIN 12828. A heating buffer tank is required for operation; additionally, a functioning return temperature boost with a sufficiently high return temperature is necessary to protect the boiler body from low return temperatures.\u003c\/p\u003e \u003cp\u003eThe hydraulic integration, system safety equipment, and connection to the flue gas system must match the specific installation. The chimney, safety valve, expansion vessel, return temperature boost, and thermal safety device must be professionally designed as part of the system planning.\u003c\/p\u003e \u003c\/div\u003e \u003cstyle\u003e .product-th{margin-top:2rem}.product-th h2{margin:0 0 1rem}.product-th__table{width:100%;border-collapse:separate;border-spacing:0}.product-th__table td{padding:.95rem 1rem;vertical-align:top}.product-th__label{font-weight:700;width:38%;color:#213670}.product-th__value{color:#1f2937}.product-th__table tr:nth-child(odd) td{background:#f4f7fb}.product-th__table tr:nth-child(even) td{background:#fafbfd} \u003c\/style\u003e \u003cdiv class=\"product-th\"\u003e \u003ch2\u003eTechnical Specifications at a Glance\u003c\/h2\u003e \u003cp\u003eThe following technical data refers to the Defro Optima HG 25 kW variant.\u003c\/p\u003e \u003ctable class=\"product-th__table\"\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eRated Output\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e25 kW\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eFuel\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003eSplit logs \/ hardwood, residual moisture 12–20%\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eCombustion Technology\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003eWood gasification\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eEfficiency\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e92.2% at full load\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eEnergy Efficiency Class\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003eA+\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eMax. Flow Temperature\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e90 °C\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eMax. Operating Pressure\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e3.0 bar\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eBoiler Class\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003eClass 5 according to EN 303-5\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eDraft Requirement\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e16 Pa\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eFlue Gas Temperature\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e127 °C\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eFlue Pipe Connection\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003eØ 130 mm\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eSafety Heat Exchanger\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003eYes, built-in\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eBuffer Tank Recommended\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003eYes, required for operation\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eHeight\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e1460 mm\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eWidth\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e620 mm\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eDepth\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e1155 mm\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eVoltage\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e230 V\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eFrequency\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e50 Hz\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003eFuse Protection\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e3.15 A\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003ePower Consumption\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003emax. 35 W\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd class=\"product-th__label\"\u003ePhases\u003c\/td\u003e \u003ctd class=\"product-th__value\"\u003e1N\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003c\/div\u003e \u003cdiv class=\"gema-section\"\u003e \u003ch2\u003eInstallation\u003c\/h2\u003e \u003cp\u003eThe boiler must be installed by qualified professionals in accordance with applicable regulations and manufacturer specifications. The boiler is intended for closed heating systems and requires a professionally designed hydraulic system with a buffer tank, return temperature boost, safety devices, and suitable water quality.\u003c\/p\u003e \u003cp\u003eBefore connecting to the flue gas system, the chimney cross-section, chimney draft, and installation conditions must be professionally checked. The electrical connection of the control unit is designed for 230 V \/ 50 Hz and may only be carried out by appropriately qualified personnel.\u003c\/p\u003e \u003c\/div\u003e \u003cdiv class=\"gema-section\"\u003e \u003ch2\u003eNotes\u003c\/h2\u003e \u003cp\u003eThe intended fuel is hardwood in split log form with suitable residual moisture. Other fuels or unsuitable materials must not be used. For proper operation, the specifications regarding return temperature, buffer tank, cleaning, maintenance, and chimney draft must be observed.\u003c\/p\u003e \u003cp\u003eThe output specification serves for the technical classification of the boiler and does not replace a heat load calculation. For planning, commissioning, flue gas measurement, and maintenance, the complete manufacturer documentation and locally applicable regulations should be considered.\u003c\/p\u003e \u003c\/div\u003e \u003cdiv class=\"gema-section\"\u003e \u003ch2\u003eScope of Delivery\u003c\/h2\u003e \u003cul\u003e \u003cli\u003eDefro Optima HG 25 kW wood gasification boiler\u003c\/li\u003e \u003cli\u003eInstallation and operating instructions\u003c\/li\u003e \u003cli\u003eWarranty card\u003c\/li\u003e \u003cli\u003eElectronic control unit\u003c\/li\u003e \u003cli\u003eInduced draft fan\u003c\/li\u003e \u003cli\u003eAnalog boiler thermometer\u003c\/li\u003e \u003cli\u003eCleaning mechanism for heat exchanger cleaning\u003c\/li\u003e \u003cli\u003eFilling and combustion chamber lining\u003c\/li\u003e \u003cli\u003eCombustion nozzle\u003c\/li\u003e \u003cli\u003eCleaning tool\u003c\/li\u003e \u003cli\u003eBuilt-in safety heat exchanger\u003c\/li\u003e \u003cli\u003eTurbulators\u003c\/li\u003e \u003c\/ul\u003e \u003c\/div\u003e","brand":"Defro","offers":[{"title":"Default Title","offer_id":49552842555740,"sku":"DOHG25","price":56073.0,"currency_code":"SEK","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0757\/7796\/6428\/files\/holzvergaserkessel-defro-optima-hg-25-kw-kfw-forderfahig-9853038.png?v=1770692485","url":"https:\/\/se.gemashop.de\/en\/products\/traforgasarpanna-defro-optima-hg-25-kw","provider":"GEMA Shop","version":"1.0","type":"link"}