{"product_id":"products-defro-dws-17-kw-festbrennstoffkessel-steinkohle","title":"DEFRO DWS 17 kW solid fuel boiler hard coal boiler","description":"\u003cp data-start=\"404\" data-end=\"755\"\u003eThe DEFRO DWS 17 kW is a manually fed solid fuel boiler for hard coal with bottom-down combustion. With an efficiency of up to 89.9%, it meets the requirements of Class 5 according to PN-EN 303-5 and is ideally suited for single-family homes. In combination with a buffer storage tank, it can be operated as a primary heating system or as a supplementary boiler.\u003c\/p\u003e  \u003chr data-start=\"757\" data-end=\"760\"\u003e  \u003ch2 data-start=\"762\" data-end=\"788\"\u003eHighlights\/Advantages\u003c\/h2\u003e  \u003cp data-start=\"790\" data-end=\"1164\"\u003e⭐ High efficiency up to 89.9% – efficient use of fuel\u003cbr data-start=\"858\" data-end=\"861\"\u003e⭐ Emission class 5 according to PN-EN 303-5 – meets strict environmental requirements\u003cbr data-start=\"935\" data-end=\"938\"\u003e⭐ Robust construction with ceramic combustion chamber – durable and easy to maintain.\u003cbr data-start=\"1014\" data-end=\"1017\"\u003e⭐ Suitable for open and closed systems according to DIN EN 12828\u003cbr data-start=\"1081\" data-end=\"1084\"\u003e⭐ Ideally combined with a buffer storage tank – optimized, low-emission combustion.\u003c\/p\u003e  \u003chr data-start=\"1166\" data-end=\"1169\"\u003e  \u003ch2 data-start=\"1171\" data-end=\"1201\"\u003eDetailed description\u003c\/h2\u003e  \u003ch3 data-start=\"1203\" data-end=\"1236\"\u003eArea of ​​application \u0026amp; Target audience\u003c\/h3\u003e  \u003cp data-start=\"1238\" data-end=\"1453\"\u003eThe DEFRO DWS 17 kW is a central heating boiler for hot water heating systems with a maximum flow temperature of 90 °C. It is suitable for single-family homes and smaller buildings with medium heat demand.\u003c\/p\u003e  \u003cp data-start=\"1455\" data-end=\"1622\"\u003eThe product is suitable for use in both open and closed heating systems according to DIN EN 12828. A buffer storage tank is mandatory in closed systems.\u003c\/p\u003e  \u003ch3 data-start=\"1624\" data-end=\"1648\"\u003eEveryday benefits\u003c\/h3\u003e  \u003cp data-start=\"1650\" data-end=\"1874\"\u003eThe boiler operates on the principle of bottom combustion. The special ceramic material in the combustion chamber promotes clean afterburning of the exhaust gases. This reduces emissions and improves efficiency.\u003c\/p\u003e  \u003cp data-start=\"1876\" data-end=\"2058\"\u003eThe large loading door allows for convenient manual feeding. The heat exchanger and combustion chamber are easily accessible via inspection openings, facilitating cleaning and maintenance.\u003c\/p\u003e  \u003ch3 data-start=\"2060\" data-end=\"2087\"\u003eTechnology \u0026amp; equipment\u003c\/h3\u003e  \u003cp data-start=\"2089\" data-end=\"2334\"\u003eThe DEFRO DWS 17 kW is a manually fed solid fuel boiler for hard coal (type 31.2 – nut coal). Alternatively, lignite briquettes or logs can be used, however, emissions measurements are only taken with hard coal.\u003c\/p\u003e  \u003cp data-start=\"2336\" data-end=\"2362\"\u003eThe boiler features:\u003c\/p\u003e  \u003cul data-start=\"2364\" data-end=\"2579\"\u003e  \u003cli data-start=\"2364\" data-end=\"2385\"\u003e  \u003cp data-start=\"2366\" data-end=\"2385\"\u003eCast iron grate\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"2386\" data-end=\"2423\"\u003e  \u003cp data-start=\"2388\" data-end=\"2423\"\u003eCeramic combustion chamber lining\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"2424\" data-end=\"2456\"\u003e  \u003cp data-start=\"2426\" data-end=\"2456\"\u003eFire draft regulator (mechanical)\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"2457\" data-end=\"2486\"\u003e  \u003cp data-start=\"2459\" data-end=\"2486\"\u003eAnalog temperature display\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"2487\" data-end=\"2527\"\u003e  \u003cp data-start=\"2489\" data-end=\"2527\"\u003eCleaning openings and turbulators\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"2528\" data-end=\"2579\"\u003e  \u003cp data-start=\"2530\" data-end=\"2579\"\u003eConnection fitting for thermal relief valve\u003c\/p\u003e  \u003c\/li\u003e  \u003c\/ul\u003e  \u003cp data-start=\"2581\" data-end=\"2722\"\u003eAn integrated safety heat exchanger is not included. An external double thermal relief valve must be installed.\u003c\/p\u003e  \u003ch3 data-start=\"2724\" data-end=\"2748\"\u003eEfficiency \u0026amp; Environment\u003c\/h3\u003e  \u003cp data-start=\"2750\" data-end=\"2896\"\u003eThe measured efficiency is 89.6–89.9% at nominal output. This means the boiler meets the requirements of class 5 according to PN-EN 303-5.\u003c\/p\u003e  \u003cp data-start=\"2898\" data-end=\"2927\"\u003eEmission values ​​at 10% O₂:\u003c\/p\u003e  \u003cul data-start=\"2929\" data-end=\"2988\"\u003e  \u003cli data-start=\"2929\" data-end=\"2947\"\u003e  \u003cp data-start=\"2931\" data-end=\"2947\"\u003eCO: 20.4 mg\/m³\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"2948\" data-end=\"2966\"\u003e  \u003cp data-start=\"2950\" data-end=\"2966\"\u003eOGC: 4.0 mg\/m³\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"2967\" data-end=\"2988\"\u003e  \u003cp data-start=\"2969\" data-end=\"2988\"\u003eDust: 14.5 mg\/m³\u003c\/p\u003e  \u003c\/li\u003e  \u003c\/ul\u003e  \u003cp data-start=\"2990\" data-end=\"3123\"\u003eThe boiler meets the requirements of the 1st Federal Immission Control Ordinance (1. BImSchV) when properly installed, adjusted and operated with suitable fuel.\u003c\/p\u003e  \u003ch3 data-start=\"3125\" data-end=\"3165\"\u003ecompatibility \u0026amp; System integration\u003c\/h3\u003e  \u003cp data-start=\"3167\" data-end=\"3341\"\u003eA buffer storage tank is essential for optimized operation. This stores excess heat energy and ensures low-emission full-load operation.\u003c\/p\u003e  \u003cp data-start=\"3343\" data-end=\"3381\"\u003eThe hydraulic connection must be equipped with:\u003c\/p\u003e  \u003cul data-start=\"3383\" data-end=\"3541\"\u003e  \u003cli data-start=\"3383\" data-end=\"3417\"\u003e  \u003cp data-start=\"3385\" data-end=\"3417\"\u003eSafety valve (max. 3 bar)\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"3418\" data-end=\"3473\"\u003e  \u003cp data-start=\"3420\" data-end=\"3473\"\u003eReturn temperature boost (minimum return temperature 65 °C)\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"3474\" data-end=\"3505\"\u003e  \u003cp data-start=\"3476\" data-end=\"3505\"\u003eThermal safety device\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"3506\" data-end=\"3541\"\u003e  \u003cp data-start=\"3508\" data-end=\"3541\"\u003eExpansion vessel according to EN 12828\u003c\/p\u003e  \u003c\/li\u003e  \u003c\/ul\u003e  \u003cp data-start=\"3543\" data-end=\"3554\"\u003etake place.\u003c\/p\u003e  \u003chr data-start=\"3556\" data-end=\"3559\"\u003e  \u003ch2 data-start=\"3561\" data-end=\"3582\"\u003eTechnical data\u003c\/h2\u003e  \u003cdiv class=\"TyagGW_tableContainer\"\u003e  \u003cdiv class=\"group TyagGW_tableWrapper flex flex-col-reverse w-fit\" tabindex=\"-1\"\u003e  \u003ctable data-start=\"3584\" data-end=\"4398\" class=\"w-fit min-w-(--thread-content-width)\"\u003e  \u003cthead data-start=\"3584\" data-end=\"3602\"\u003e  \u003ctr data-start=\"3584\" data-end=\"3602\"\u003e  \u003cth data-start=\"3584\" data-end=\"3594\" data-col-size=\"sm\" class=\"\"\u003efeature\u003c\/th\u003e  \u003cth data-start=\"3594\" data-end=\"3602\" data-col-size=\"md\" class=\"\"\u003eValue\u003c\/th\u003e  \u003c\/tr\u003e  \u003c\/thead\u003e  \u003ctbody data-start=\"3623\" data-end=\"4398\"\u003e  \u003ctr data-start=\"3623\" data-end=\"3645\"\u003e  \u003ctd data-start=\"3623\" data-end=\"3636\" data-col-size=\"sm\"\u003eManufacturer\u003c\/td\u003e  \u003ctd data-start=\"3636\" data-end=\"3645\" data-col-size=\"md\"\u003eDEFRO\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3646\" data-end=\"3665\"\u003e  \u003ctd data-start=\"3646\" data-end=\"3655\" data-col-size=\"sm\"\u003eModel\u003c\/td\u003e  \u003ctd data-start=\"3655\" data-end=\"3665\" data-col-size=\"md\"\u003eDWS 17\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3666\" data-end=\"3719\"\u003e  \u003ctd data-start=\"3666\" data-end=\"3679\" data-col-size=\"sm\"\u003eProduct type\u003c\/td\u003e  \u003ctd data-start=\"3679\" data-end=\"3719\" data-col-size=\"md\"\u003eManually fed solid fuel boiler\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3720\" data-end=\"3749\"\u003e  \u003ctd data-start=\"3720\" data-end=\"3740\" data-col-size=\"sm\"\u003eNominal heat output\u003c\/td\u003e  \u003ctd data-start=\"3740\" data-end=\"3749\" data-col-size=\"md\"\u003e17 kW\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3750\" data-end=\"3780\"\u003e  \u003ctd data-start=\"3750\" data-end=\"3775\" data-col-size=\"sm\"\u003eEnergy efficiency class\u003c\/td\u003e  \u003ctd data-start=\"3775\" data-end=\"3780\" data-col-size=\"md\"\u003eB\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3781\" data-end=\"3828\"\u003e  \u003ctd data-start=\"3781\" data-end=\"3813\" data-col-size=\"sm\"\u003eEfficiency at rated power\u003c\/td\u003e  \u003ctd data-start=\"3813\" data-end=\"3828\" data-col-size=\"md\"\u003e89.6–89.9%\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3829\" data-end=\"3860\"\u003e  \u003ctd data-start=\"3829\" data-end=\"3848\" data-col-size=\"sm\"\u003eExhaust gas mass flow\u003c\/td\u003e  \u003ctd data-start=\"3848\" data-end=\"3860\" data-col-size=\"md\"\u003e10.2 g\/s\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3861\" data-end=\"3884\"\u003e  \u003ctd data-start=\"3861\" data-end=\"3876\" data-col-size=\"sm\"\u003eCO₂ emissions\u003c\/td\u003e  \u003ctd data-start=\"3876\" data-end=\"3884\" data-col-size=\"md\"\u003e11%\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3885\" data-end=\"3913\"\u003e  \u003ctd data-start=\"3885\" data-end=\"3903\" data-col-size=\"sm\"\u003eExhaust gas temperature\u003c\/td\u003e  \u003ctd data-start=\"3903\" data-end=\"3913\" data-col-size=\"md\"\u003e149 °C\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3914\" data-end=\"3952\"\u003e  \u003ctd data-start=\"3914\" data-end=\"3941\" data-col-size=\"sm\"\u003ePermissible operating pressure\u003c\/td\u003e  \u003ctd data-start=\"3941\" data-end=\"3952\" data-col-size=\"md\"\u003e2.5 bar\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3953\" data-end=\"3988\"\u003e  \u003ctd data-start=\"3953\" data-end=\"3979\" data-col-size=\"sm\"\u003eMaximum operating temperature\u003c\/td\u003e  \u003ctd data-start=\"3979\" data-end=\"3988\" data-col-size=\"md\"\u003e85 °C\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"3989\" data-end=\"4028\"\u003e  \u003ctd data-start=\"3989\" data-end=\"4019\" data-col-size=\"sm\"\u003eMinimum operating temperature\u003c\/td\u003e  \u003ctd data-start=\"4019\" data-end=\"4028\" data-col-size=\"md\"\u003e75 °C\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4029\" data-end=\"4068\"\u003e  \u003ctd data-start=\"4029\" data-end=\"4059\" data-col-size=\"sm\"\u003eMinimum return temperature\u003c\/td\u003e  \u003ctd data-start=\"4059\" data-end=\"4068\" data-col-size=\"md\"\u003e60 °C\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4069\" data-end=\"4102\"\u003e  \u003ctd data-start=\"4069\" data-end=\"4090\" data-col-size=\"sm\"\u003eboiler water content\u003c\/td\u003e  \u003ctd data-start=\"4090\" data-end=\"4102\" data-col-size=\"md\"\u003e92 liters\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4103\" data-end=\"4123\"\u003e  \u003ctd data-start=\"4103\" data-end=\"4113\" data-col-size=\"sm\"\u003eWeight\u003c\/td\u003e  \u003ctd data-start=\"4113\" data-end=\"4123\" data-col-size=\"md\"\u003e411 kg\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4124\" data-end=\"4153\"\u003e  \u003ctd data-start=\"4124\" data-end=\"4141\" data-col-size=\"sm\"\u003eExhaust connection\u003c\/td\u003e  \u003ctd data-start=\"4141\" data-end=\"4153\" data-col-size=\"md\"\u003eØ 159 mm\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4154\" data-end=\"4185\"\u003e  \u003ctd data-start=\"4154\" data-end=\"4175\" data-col-size=\"sm\"\u003eFlow\/Return\u003c\/td\u003e  \u003ctd data-start=\"4175\" data-end=\"4185\" data-col-size=\"md\"\u003e1½\u0026quot; internal thread\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4186\" data-end=\"4234\"\u003e  \u003ctd data-start=\"4186\" data-end=\"4225\" data-col-size=\"sm\"\u003eRequired chimney negative pressure\u003c\/td\u003e  \u003ctd data-start=\"4225\" data-end=\"4234\" data-col-size=\"md\"\u003e21 Pa\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4235\" data-end=\"4268\"\u003e  \u003ctd data-start=\"4235\" data-end=\"4259\" data-col-size=\"sm\"\u003eBurning time per filling\u003c\/td\u003e  \u003ctd data-start=\"4259\" data-end=\"4268\" data-col-size=\"md\"\u003e2–4 h\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4269\" data-end=\"4328\"\u003e  \u003ctd data-start=\"4269\" data-end=\"4282\" data-col-size=\"sm\"\u003efuel\u003c\/td\u003e  \u003ctd data-start=\"4282\" data-end=\"4328\" data-col-size=\"md\"\u003eBituminous coal (Type 31.2 – Nut coal 20–25 mm)\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4329\" data-end=\"4372\"\u003e  \u003ctd data-start=\"4329\" data-end=\"4338\" data-col-size=\"sm\"\u003eStandards\u003c\/td\u003e  \u003ctd data-start=\"4338\" data-end=\"4372\" data-col-size=\"md\"\u003ePN-EN 303-5:2012, DIN EN 12828\u003c\/td\u003e  \u003c\/tr\u003e  \u003ctr data-start=\"4373\" data-end=\"4398\"\u003e  \u003ctd data-start=\"4373\" data-end=\"4392\" data-col-size=\"sm\"\u003eCE marking\u003c\/td\u003e  \u003ctd data-start=\"4392\" data-end=\"4398\" data-col-size=\"md\"\u003eYes\u003c\/td\u003e  \u003c\/tr\u003e  \u003c\/tbody\u003e  \u003c\/table\u003e  \u003c\/div\u003e  \u003c\/div\u003e  \u003cp data-start=\"4400\" data-end=\"4422\"\u003eDimensions (17 kW):\u003c\/p\u003e  \u003cul data-start=\"4424\" data-end=\"4490\"\u003e  \u003cli data-start=\"4424\" data-end=\"4446\"\u003e  \u003cp data-start=\"4426\" data-end=\"4446\"\u003eWidth (A): 520 mm\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4447\" data-end=\"4468\"\u003e  \u003cp data-start=\"4449\" data-end=\"4468\"\u003eDepth (B): 594 mm\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4469\" data-end=\"4490\"\u003e  \u003cp data-start=\"4471\" data-end=\"4490\"\u003eHeight (D): 1315 mm\u003c\/p\u003e  \u003c\/li\u003e  \u003c\/ul\u003e  \u003chr data-start=\"4492\" data-end=\"4495\"\u003e  \u003ch2 data-start=\"4497\" data-end=\"4514\"\u003eScope of delivery\u003c\/h2\u003e  \u003cul data-start=\"4516\" data-end=\"4722\"\u003e  \u003cli data-start=\"4516\" data-end=\"4572\"\u003e  \u003cp data-start=\"4518\" data-end=\"4572\"\u003eDEFRO DWS 17 kW boiler (encased and insulated)\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4573\" data-end=\"4595\"\u003e  \u003cp data-start=\"4575\" data-end=\"4595\"\u003eCleaning tool\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4596\" data-end=\"4630\"\u003e  \u003cp data-start=\"4598\" data-end=\"4630\"\u003eFirebricks for combustion chamber\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4631\" data-end=\"4665\"\u003e  \u003cp data-start=\"4633\" data-end=\"4665\"\u003eTurbulators for heat exchangers\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4666\" data-end=\"4685\"\u003e  \u003cp data-start=\"4668\" data-end=\"4685\"\u003eFire draft regulator\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4686\" data-end=\"4722\"\u003e  \u003cp data-start=\"4688\" data-end=\"4722\"\u003eAssembly and operating instructions\u003c\/p\u003e  \u003c\/li\u003e  \u003c\/ul\u003e  \u003chr data-start=\"4724\" data-end=\"4727\"\u003e  \u003ch2 data-start=\"4729\" data-end=\"4754\"\u003eAccessories\/Recommendation\u003c\/h2\u003e  \u003cp data-start=\"4756\" data-end=\"4815\"\u003eFor safe and efficient operation, we recommend:\u003c\/p\u003e  \u003cul data-start=\"4817\" data-end=\"5026\"\u003e  \u003cli data-start=\"4817\" data-end=\"4872\"\u003e  \u003cp data-start=\"4819\" data-end=\"4872\"\u003eBuffer storage tank (suitable models under gemashop.de)\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4873\" data-end=\"4928\"\u003e  \u003cp data-start=\"4875\" data-end=\"4928\"\u003eDouble thermal safety device (e.g. Caleffi)\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4929\" data-end=\"4956\"\u003e  \u003cp data-start=\"4931\" data-end=\"4956\"\u003eBoiler safety group\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4957\" data-end=\"4984\"\u003e  \u003cp data-start=\"4959\" data-end=\"4984\"\u003eReturn flow boost valve\u003c\/p\u003e  \u003c\/li\u003e  \u003cli data-start=\"4985\" data-end=\"5026\"\u003e  \u003cp data-start=\"4987\" data-end=\"5026\"\u003eSuitable flue pipes and draft regulators\u003c\/p\u003e  \u003c\/li\u003e  \u003c\/ul\u003e  \u003cp data-start=\"5028\" data-end=\"5119\"\u003eSuitable components can be found in the heating technology accessories section at:\u003cbr data-start=\"5095\" data-end=\"5098\"\u003e\u003ca data-start=\"5098\" data-end=\"5117\" rel=\"noopener\" class=\"decorated-link\" href=\"https:\/\/gemashop.de\"\u003ehttps:\/\/gemashop.de\u003cspan aria-hidden=\"true\" class=\"ms-0.5 inline-block align-middle leading-none\"\u003e\u003csvg xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"20\" height=\"20\" aria-hidden=\"true\" data-rtl-flip=\"\" class=\"block h-[0.75em] w-[0.75em] stroke-current stroke-[0.75]\"\u003e\u003cuse fill=\"currentColor\" href=\"\/cdn\/assets\/sprites-core-jxe2m7va.svg#304883\"\u003e\u003c\/use\u003e\u003c\/svg\u003e\u003c\/span\u003e\u003c\/a\u003e\u003c\/p\u003e  \u003chr data-start=\"5121\" data-end=\"5124\"\u003e  \u003ch2 data-start=\"5126\" data-end=\"5161\"\u003eAssembly \u0026amp; Safety instructions\u003c\/h2\u003e  \u003cp data-start=\"5163\" data-end=\"5248\"\u003eInstallation must be carried out exclusively by an approved specialist company.\u003c\/p\u003e  \u003cp data-start=\"5250\" data-end=\"5467\"\u003ePrior to commissioning, the approval of the responsible chimney sweep is required. The boiler may only be installed on a non-combustible surface. Minimum distances to combustible building components must be observed.\u003c\/p\u003e  \u003cp data-start=\"5469\" data-end=\"5608\"\u003eA thermal relief valve is mandatory. Operation without a buffer tank in closed systems is not permitted.\u003c\/p\u003e  \u003chr data-start=\"5610\" data-end=\"5613\"\u003e  \u003ch2 data-start=\"5615\" data-end=\"5623\"\u003eFAQ\u003c\/h2\u003e  \u003cp data-start=\"5625\" data-end=\"5840\"\u003e\u003cstrong data-start=\"5625\" data-end=\"5665\"\u003e1. Which fuels are permitted?\u003c\/strong\u003e\u003cbr data-start=\"5665\" data-end=\"5668\"\u003eThe main fuel is hard coal (type 31.2 – nut coal 20–25 mm). Lignite briquettes and firewood are technically possible, but not approved for emission measurements.\u003c\/p\u003e  \u003cp data-start=\"5842\" data-end=\"6017\"\u003e\u003cstrong data-start=\"5842\" data-end=\"5883\"\u003e2. Does the boiler meet the requirements of the first...BImSchV?\u003c\/strong\u003e\u003cbr data-start=\"5883\" data-end=\"5886\"\u003eYes, with correct installation, adjustment and suitable fuel, it meets the requirements of class 5 according to PN-EN 303-5.\u003c\/p\u003e  \u003cp data-start=\"6019\" data-end=\"6191\"\u003e\u003cstrong data-start=\"6019\" data-end=\"6059\"\u003e3. Is a buffer storage tank necessary?\u003c\/strong\u003e\u003cbr data-start=\"6059\" data-end=\"6062\"\u003eYes. The buffer storage tank is mandatory for proper operation and a warranty requirement in closed systems.\u003c\/p\u003e  \u003cp data-start=\"6193\" data-end=\"6303\"\u003e\u003cstrong data-start=\"6193\" data-end=\"6239\"\u003e4. Is a return flow boost required?\u003c\/strong\u003e\u003cbr data-start=\"6239\" data-end=\"6242\"\u003eYes. The return temperature must not fall below 65 °C.\u003c\/p\u003e  \u003cp data-start=\"6305\" data-end=\"6434\"\u003e\u003cstrong data-start=\"6305\" data-end=\"6356\"\u003e5. Is a safety heat exchanger integrated?\u003c\/strong\u003e\u003cbr data-start=\"6356\" data-end=\"6359\"\u003eNo. An external thermal safety device must be installed.\u003c\/p\u003e  \u003cp data-start=\"6436\" data-end=\"6534\"\u003e\u003cstrong data-start=\"6436\" data-end=\"6473\"\u003e6. What is the efficiency?\u003c\/strong\u003e\u003cbr data-start=\"6473\" data-end=\"6476\"\u003eThe efficiency is 89.6–89.9% at rated power.\u003c\/p\u003e  \u003chr data-start=\"6536\" data-end=\"6539\"\u003e  \u003ch2 data-start=\"6541\" data-end=\"6551\"\u003eConclusion\u003c\/h2\u003e  \u003cp data-start=\"6553\" data-end=\"6827\"\u003eThe DEFRO DWS 17 kW is a robust and efficient solid fuel boiler for use with hard coal. Combined with a buffer storage tank, it offers a reliable and standards-compliant heating solution for residential buildings. Order now and modernize your heating system with reliability.\u003c\/p\u003e","brand":"Defro","offers":[{"title":"Default Title","offer_id":47725610172764,"sku":"DDWS17","price":1900.74,"currency_code":"EUR","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0757\/7796\/6428\/files\/defro-dws-17-kw-festbrennstoffkessel-kohlekessel-klasse-5-7591331.webp?v=1770693273","url":"https:\/\/si.gemashop.de\/hr\/products\/products-defro-dws-17-kw-solid-fuel-boiler-hard-coal-1","provider":"GEMA Shop","version":"1.0","type":"link"}