{"product_id":"a-o-smith-100109721-upper-probe-hot-surface-igniter","title":"A.o. Smith 100109721 Upper Probe Hot Surface Igniter","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\n\u003cp\u003eThe A.O. SMITH 100109721 is a hot surface igniter serving as the upper probe for the inner control assembly on commercial water heaters. It initiates combustion by generating the heat needed to light the burner on natural gas and propane-fired units. This igniter is a direct-replacement component for licensed plumbers and HVAC technicians servicing A.O. SMITH commercial water heater lines. Proper igniter function is critical to reliable system startup, and a failed or cracked igniter is a common cause of no-heat or lockout conditions on standing-pilot-free systems.\u003c\/p\u003e\n\u003cp\u003eThis igniter is designed for use in commercial water heater applications running on natural gas or propane. It is specified for A.O. SMITH BTH, SUF, and HCG series units across a range of sizes including the 60-120, 100-150, 100-199, and 100-250 models. These are high-input commercial water heaters typically found in multifamily residential buildings, light commercial facilities, and institutional settings. Installation is performed by licensed plumbers or gas service technicians during routine maintenance or burner assembly service calls.\u003c\/p\u003e\n\u003ch4\u003eKey Features\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003eFunctions as the upper probe within the inner control assembly for reliable ignition sequencing\u003c\/li\u003e\n  \u003cli\u003eCompatible with both natural gas and propane fuel types\u003c\/li\u003e\n  \u003cli\u003eHigh-efficiency design suited for commercial-grade water heating systems\u003c\/li\u003e\n  \u003cli\u003eDirect OEM replacement for BTH, SUF, and HCG series A.O. SMITH units\u003c\/li\u003e\n  \u003cli\u003eAddresses common ignition failure and burner lockout conditions\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch4\u003eCompatibility\u003c\/h4\u003e\n\u003cp\u003eDesigned for use with A.O. SMITH BTH, SUF, and HCG series commercial water heaters, including models 60-120, 100-150, 100-199, and 100-250, on natural gas and propane systems.\u003c\/p\u003e\n\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\n\u003cp\u003eInstallation should be performed by a licensed plumber or gas service technician in accordance with local codes and the IFGC. Shut off the gas supply and disconnect power to the unit before removing the burner access panel or handling the igniter assembly. Hot surface igniters are fragile — avoid contact with bare skin, as oils can cause premature failure. Verify igniter resistance and circuit continuity with a multimeter before completing reassembly.\u003c\/p\u003e\n\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\n\u003cul\u003e\n  \u003cli\u003e\n\u003cstrong\u003eApplication\u003c\/strong\u003e: Heating\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eFuel Type\u003c\/strong\u003e: Natural Gas, Propane\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eComponent Role\u003c\/strong\u003e: Upper Probe, Inner Control Assembly\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompatible Series\u003c\/strong\u003e: BTH, SUF, HCG\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eCompatible Size Range\u003c\/strong\u003e: 60-120, 100-150, 100-199, 100-250\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: A.O. SMITH\u003c\/li\u003e\n  \u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 100109721\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"TAILWIND","offers":[{"title":"Default Title","offer_id":51150394589490,"sku":"100109721","price":146.52,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/305989526.jpg?v=1778611098","url":"https:\/\/voomisupply.com\/products\/a-o-smith-100109721-upper-probe-hot-surface-igniter","provider":"Voomi Supply","version":"1.0","type":"link"}