{"product_id":"ao-smith-100074218-burner-window-tankless-water-heater","title":"Ao Smith 100074218 Burner Window Tankless Water Heater","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe AO SMITH 100074218 is a replacement burner window designed for use in AO Smith tankless water heater units. The burner window provides a sealed viewing port in the combustion chamber assembly, allowing technicians to inspect burner operation without compromising the integrity of the heat exchanger enclosure. This part is a direct OEM-style replacement intended for field service and routine maintenance. Licensed plumbers and HVAC technicians performing burner assembly service or combustion inspection work will encounter this component on both natural gas and LP-fired AO Smith tankless models across multiple product lines.\u003c\/p\u003e\n\u003cp\u003eThis burner window is compatible with a wide range of AO Smith tankless water heater models spanning indoor, outdoor, direct-vent, and open-combustion configurations in both natural gas and liquid propane fuel types. The part covers residential and light commercial tankless units from the T-series and TK-series product families. Verified compatible models are listed in the compatibility section below.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eDirect OEM replacement part for AO Smith tankless water heater burner assemblies\u003c\/li\u003e\n  \u003cli\u003eCompatible with both natural gas and LP-fired units across multiple model variants\u003c\/li\u003e\n  \u003cli\u003eSupports indoor, outdoor, direct-vent, and open-combustion installation configurations\u003c\/li\u003e\n  \u003cli\u003eDesigned for field service and maintenance applications\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eVerified compatible with the following AO Smith tankless water heater models: T-H3M-DV (LP), T-K3-SP (LP), TK-540P-NEH (NG), TK-310U-I (NG\/LP), TK-110U-I (NG\/LP), T-M50 (NG), T-D2U-OS (NG), T-H3J-OS (LP), T-KJR2-IN (NG), T-KJR2U-OS (NG), TK-540P-PIH (LP), TK-510U-E (NG\/LP), T-H3S-DV (LP), T-M32-ASME (LP), T-H2S-OS (LP), T-K4-IN (LP), T-H2-DV (LP), T-K3-OS (NG), T-K3-OS (LP), T-H3M-OS (LP), TK-540P-NIH (NG), TK-310U-E (NG\/LP), T-H2-OS (NG), T-M32-ASME (NG), T-H2S-DV (NG), T-K4-OS (NG), T-H3-OS (NG), TK-510U-I (NG\/LP), TK-110U-E (NG\/LP), T-K4U-OS (NG), T-H2-OS (LP), T-M50-ASME (LP), T-M32 (LP), T-H3-DV (NG), T-H3M-OS (NG), T-K4U-IN (NG), T-H3-DV (LP), T-H2S-DV (LP), T-H3M-DV (NG), T-H2S-OS (NG), T-D2-OS (LP), T-H3J-OS (NG), T-K3-SP (NG), T-H2-DV (NG), T-M50 (LP), T-K3-PRO (LP), T-H3S-OS (NG), T-D2-IN (LP), T-H3J-DV (LP), T-M32 (NG), T-H3S-OS (LP), T-K4-IN (NG), T-M50-ASME (NG), T-K4-OS (LP), T-KJR2U-IN (NG), T-K3 (LP), T-D2-IN (NG), T-KJR2-OS (LP), T-H3J-DV (NG), T-D2-OS (NG), T-H3S-DV (NG), T-KJR2-IN (LP), T-K3-PRO (NG), T-H3-OS (LP), T-KJR2-OS (NG), T-D2U-IN (NG), T-K3 (NG), TK-540P-PEH (LP).\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eBurner window replacement on tankless water heaters should be performed by a licensed plumber or qualified HVAC technician. Before beginning any burner assembly service, shut off the gas supply at the service valve and disconnect power to the unit. Allow the heat exchanger and combustion chamber to cool fully before handling internal components. Verify the replacement part seats and seals correctly before restoring gas and power and performing a test fire.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApplication\u003c\/strong\u003e: Replacement Part\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eStandard Information\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: AO SMITH\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 100074218\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"TAILWIND","offers":[{"title":"Default Title","offer_id":51149576569138,"sku":"100074218","price":14.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/305987375.jpg?v=1778597571","url":"https:\/\/voomisupply.com\/products\/ao-smith-100074218-burner-window-tankless-water-heater","provider":"Voomi Supply","version":"1.0","type":"link"}