{"product_id":"navien-lcb700-blue-flame-28kw-ls-internal-system-oil-boiler","title":"Navien LCB700 Blue Flame 28kW LS Internal System Oil Boiler","description":"\u003cdiv style=\"font-size:16px; max-width:900px; margin:0 auto; font-family:Arial, Helvetica, sans-serif; color:#222;\"\u003e\n\u003cdiv style=\"line-height:1.65;color:#222;margin-bottom:20px;\"\u003eThe \u003cstrong\u003eNavien LCB700 Blue Flame 21kW LSX\u003c\/strong\u003e is an \u003cstrong\u003eexternal, floor-standing oil system boiler\u003c\/strong\u003e, sited outside the building envelope and designed to work with a separate hot water cylinder. Built around \u003cstrong\u003eBlue Flame combustion technology\u003c\/strong\u003e and a stainless steel heat exchanger, it was the first oil boiler on the UK market to offer an \u003cstrong\u003eA+ energy rating\u003c\/strong\u003e when combined with three Smart Plus room thermostats.\u003c\/div\u003e\n\u003cdiv style=\"display:flex;flex-wrap:wrap;gap:8px;margin:18px 0 26px;\"\u003e\n\u003cdiv style=\"flex:1;min-width:110px;background:#008377CF;color:#fff;border-radius:8px;padding:14px 10px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:19px;font-weight:800;line-height:1.15;\"\u003e21kW\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;opacity:.92;margin-top:4px;\"\u003eHeat Output\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;background:#008377CF;color:#fff;border-radius:8px;padding:14px 10px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:19px;font-weight:800;line-height:1.15;\"\u003e93%\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;opacity:.92;margin-top:4px;\"\u003eErP Efficiency (A)\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;background:#008377CF;color:#fff;border-radius:8px;padding:14px 10px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:19px;font-weight:800;line-height:1.15;\"\u003e20m \/ 21m\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;opacity:.92;margin-top:4px;\"\u003eMax Horiz \/ Vert Flue\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;background:#008377CF;color:#fff;border-radius:8px;padding:14px 10px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:19px;font-weight:800;line-height:1.15;\"\u003eBlue Flame\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;opacity:.92;margin-top:4px;\"\u003eCombustion Technology\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;background:#008377CF;color:#fff;border-radius:8px;padding:14px 10px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:19px;font-weight:800;line-height:1.15;\"\u003e10 yrs\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;opacity:.92;margin-top:4px;\"\u003eParts \u0026amp; Labour Warranty\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"flex:1;min-width:110px;background:#008377CF;color:#fff;border-radius:8px;padding:14px 10px;text-align:center;\"\u003e\n\u003cdiv style=\"font-size:19px;font-weight:800;line-height:1.15;\"\u003e72kg\u003c\/div\u003e\n\u003cdiv style=\"font-size:12px;opacity:.92;margin-top:4px;\"\u003eLift Weight\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#fdecea;border-left:5px solid #c0392b;border-radius:0 8px 8px 0;padding:14px 18px;margin:16px 0;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#8a1f13;font-size:14px;margin-bottom:5px;\"\u003eOFTEC Registration Required\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;color:#333;line-height:1.6;\"\u003eInstallation, commissioning and servicing of this oil-fired boiler must be carried out by an \u003cstrong\u003eOFTEC registered technician\u003c\/strong\u003e. A completed commissioning checklist must be left with the end user, and the flue and oil supply pipework must be installed in accordance with the manufacturer's installation and operation manual and current OFTEC\/Building Regulations requirements.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#fff8e6;border-left:5px solid #b8860b;border-radius:0 8px 8px 0;padding:14px 18px;margin:16px 0;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#7a5900;font-size:14px;margin-bottom:5px;\"\u003eSystem Boiler, External Installation — Cylinder Required Separately\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;color:#333;line-height:1.6;\"\u003eThis is a \u003cstrong\u003esystem boiler\u003c\/strong\u003e, not a combi, and requires a separate unvented or vented hot water cylinder, which is not included in this listing. It is also an \u003cstrong\u003eexternal model\u003c\/strong\u003e, designed for floor-standing siting outside the building in a suitable weatherproof location, not for internal cupboard installation.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-size:18px;font-weight:700;color:#00594F;border-bottom:3px solid #008377CF;padding-bottom:8px;margin:30px 0 14px;\"\u003eWhy This Boiler\u003c\/div\u003e\n\u003cdiv style=\"display:grid;grid-template-columns:1fr 1fr;gap:12px;margin:18px 0 26px;\"\u003e\n\u003cdiv style=\"background:#e6f4f2;border-left:4px solid #008377CF;border-radius:0 6px 6px 0;padding:14px 16px;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#00594F;font-size:14.5px;margin-bottom:6px;\"\u003eBlue Flame Combustion Technology\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;color:#333;line-height:1.6;\"\u003eDelivers \u003cstrong\u003esuperior combustion efficiency and ultra-low NOx emissions\u003c\/strong\u003e compared with conventional yellow-flame oil burners, while maintaining strong reliability.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#e6f4f2;border-left:4px solid #008377CF;border-radius:0 6px 6px 0;padding:14px 16px;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#00594F;font-size:14.5px;margin-bottom:6px;\"\u003eHVO Compatible\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;color:#333;line-height:1.6;\"\u003eThe boiler is compatible with \u003cstrong\u003eHydrotreated Vegetable Oil (HVO)\u003c\/strong\u003e, a renewable drop-in alternative to kerosene, supporting a lower-carbon transition for off-grid properties.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#e6f4f2;border-left:4px solid #008377CF;border-radius:0 6px 6px 0;padding:14px 16px;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#00594F;font-size:14.5px;margin-bottom:6px;\"\u003eLong Flue Runs\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;color:#333;line-height:1.6;\"\u003eSupports up to \u003cstrong\u003e20m horizontal or 21m vertical\u003c\/strong\u003e flue lengths, giving flexibility when siting an external unit away from a convenient wall penetration point.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#e6f4f2;border-left:4px solid #008377CF;border-radius:0 6px 6px 0;padding:14px 16px;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#00594F;font-size:14.5px;margin-bottom:6px;\"\u003eCombined PRV\/Condensate Drain\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;color:#333;line-height:1.6;\"\u003eA single combined \u003cstrong\u003epressure relief valve and condensate drain\u003c\/strong\u003e simplifies pipework and speeds up installation compared with boilers requiring separate connections.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#e6f4f2;border-left:4px solid #008377CF;border-radius:0 6px 6px 0;padding:14px 16px;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#00594F;font-size:14.5px;margin-bottom:6px;\"\u003eStainless Steel Heat Exchanger\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;color:#333;line-height:1.6;\"\u003eBuilt for \u003cstrong\u003eoptimum durability and long-term efficiency\u003c\/strong\u003e, resisting the corrosive effects of acidic condensate over the working life of the boiler.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"background:#e6f4f2;border-left:4px solid #008377CF;border-radius:0 6px 6px 0;padding:14px 16px;\"\u003e\n\u003cdiv style=\"font-weight:700;color:#00594F;font-size:14.5px;margin-bottom:6px;\"\u003e10-Year Warranty as Standard\u003c\/div\u003e\n\u003cdiv style=\"font-size:14px;color:#333;line-height:1.6;\"\u003eNavien back the LCB700 Blue Flame range with a \u003cstrong\u003e10-year parts and labour warranty\u003c\/strong\u003e included as standard, without needing separate registration steps.\u003c\/div\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e\n\u003cdiv style=\"font-size:18px;font-weight:700;color:#00594F;border-bottom:3px solid #008377CF;padding-bottom:8px;margin:30px 0 14px;\"\u003eTechnical Specification\u003c\/div\u003e\n\u003cdiv style=\"overflow-x:auto;margin:18px 0 26px;\"\u003e\u003ctable style=\"width:100%;border-collapse:collapse;\"\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"background:#008377CF;color:#fff;font-weight:700;padding:9px 14px;font-size:13px;letter-spacing:.04em;text-transform:uppercase;\"\u003eGeneral\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eArticle number\u003c\/td\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003ePLCB0021SH002 (21-LSX)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eBoiler type\u003c\/td\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003eExternal, floor-standing, room-sealed oil system boiler\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eFuel type\u003c\/td\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003eKerosene (28-second oil), HVO compatible\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eDimensions\u003c\/td\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003e470 x 600 x 860 mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eGuarantee\u003c\/td\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003e10 years parts and labour\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"background:#008377CF;color:#fff;font-weight:700;padding:9px 14px;font-size:13px;letter-spacing:.04em;text-transform:uppercase;\"\u003eHeating Performance\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eHeat output (80\/60°C)\u003c\/td\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003e16 – 21 kW\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eHeat output (50\/30°C, condensing)\u003c\/td\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003e23.0 kW\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"background:#008377CF;color:#fff;font-weight:700;padding:9px 14px;font-size:13px;letter-spacing:.04em;text-transform:uppercase;\"\u003ePerformance \u0026amp; Emissions\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eErP efficiency\u003c\/td\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003eA (93%) — A+ (98%) with 3x Smart Plus controls\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eNOx emission rate\u003c\/td\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003e57.2 mg\/kWh\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eLift weight\u003c\/td\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003e72 kg\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\u003ctd colspan=\"2\" style=\"background:#008377CF;color:#fff;font-weight:700;padding:9px 14px;font-size:13px;letter-spacing:.04em;text-transform:uppercase;\"\u003eFlue\u003c\/td\u003e\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eFlue diameter\u003c\/td\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003eCoaxial plastic 60\/100mm\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eMax. horizontal flue length\u003c\/td\u003e\n\u003ctd style=\"background:#ffffff;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003e20 m\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;font-weight:600;color:#333;font-size:14px;width:44%;border-bottom:1px solid #e2e2e2;\"\u003eMax. vertical flue length\u003c\/td\u003e\n\u003ctd style=\"background:#f2faf9;padding:9px 14px;color:#222;font-size:14px;border-bottom:1px solid #e2e2e2;\"\u003e21 m\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003c\/div\u003e\n\u003cdiv style=\"font-size:18px;font-weight:700;color:#00594F;border-bottom:3px solid #008377CF;padding-bottom:8px;margin:30px 0 14px;\"\u003eFrequently Asked Questions\u003c\/div\u003e\n\u003cdiv style=\"margin:18px 0 10px;\"\u003e\n\u003cdetails style=\"border:1px solid #cde3e1;border-radius:8px;margin-bottom:10px;overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:12px 18px;font-weight:700;font-size:14.5px;cursor:pointer;list-style:none;\"\u003eDoes this boiler include a hot water cylinder?\u003c\/summary\u003e\u003cdiv style=\"padding:14px 18px;font-size:14px;color:#333;line-height:1.65;background:#fff;\"\u003eNo. As a system boiler, the LCB700 Blue Flame 21kW LSX requires a separate hot water cylinder to store and deliver domestic hot water. Cylinders are sold separately.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #cde3e1;border-radius:8px;margin-bottom:10px;overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:12px 18px;font-weight:700;font-size:14.5px;cursor:pointer;list-style:none;\"\u003eWhat's the difference between the internal and external LCB700 models?\u003c\/summary\u003e\u003cdiv style=\"padding:14px 18px;font-size:14px;color:#333;line-height:1.65;background:#fff;\"\u003eThe external (LSX) model is a floor-standing unit designed to be sited outside the building envelope in a weatherproof location, whereas the internal (LS) model is designed for indoor installation.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #cde3e1;border-radius:8px;margin-bottom:10px;overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:12px 18px;font-weight:700;font-size:14.5px;cursor:pointer;list-style:none;\"\u003eCan this boiler run on HVO instead of kerosene?\u003c\/summary\u003e\u003cdiv style=\"padding:14px 18px;font-size:14px;color:#333;line-height:1.65;background:#fff;\"\u003eYes, the LCB700 Blue Flame range is HVO compatible, allowing use of Hydrotreated Vegetable Oil as a renewable drop-in alternative to standard kerosene, subject to local fuel availability.\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #cde3e1;border-radius:8px;margin-bottom:10px;overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:12px 18px;font-weight:700;font-size:14.5px;cursor:pointer;list-style:none;\"\u003eHow do I reach the A+ ErP rating on this boiler?\u003c\/summary\u003e\u003cdiv style=\"padding:14px 18px;font-size:14px;color:#333;line-height:1.65;background:#fff;\"\u003eThe boiler achieves ErP A (93%) as standard. Fitting three Smart Plus room thermostats raises the overall system rating to ErP A+ (98%).\u003c\/div\u003e\u003c\/details\u003e\u003cdetails style=\"border:1px solid #cde3e1;border-radius:8px;margin-bottom:10px;overflow:hidden;\"\u003e\u003csummary style=\"background:#008377CF;color:#fff;padding:12px 18px;font-weight:700;font-size:14.5px;cursor:pointer;list-style:none;\"\u003eCan I install this boiler myself?\u003c\/summary\u003e\u003cdiv style=\"padding:14px 18px;font-size:14px;color:#333;line-height:1.65;background:#fff;\"\u003eNo. UK regulations require that oil-fired boiler installation, commissioning and servicing work is carried out by an OFTEC registered technician.\u003c\/div\u003e\u003c\/details\u003e\n\u003c\/div\u003e\n\u003c\/div\u003e","brand":"Navien","offers":[{"title":"Default Title","offer_id":65142916219229,"sku":"PLCB0028SH001","price":1975.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0958\/2051\/3629\/files\/NavienLCB700BlueFlame28kWLSInternalSystemOilBoiler.jpg?v=1783093761","url":"https:\/\/qualityheating.co.uk\/products\/navien-lcb700-blue-flame-28kw-ls-internal-system-oil-boiler","provider":"AIZO Quality Heating","version":"1.0","type":"link"}