{"product_id":"ruud-47-104990-03-gas-furnace-limit-switch-auto-reset","title":"Ruud 47-104990-03 Gas Furnace Limit Switch Auto Reset","description":"\u003ch3\u003eProduct Description\u003c\/h3\u003e\u003cp\u003eThe RUUD 47-104990-03 is a single-pole, normally closed, auto-reset limit switch designed for gas furnace overheat protection. It opens at 170 degrees F and resets automatically when the temperature drops back to 150 degrees F, interrupting the burner circuit before heat exchanger temperatures reach damaging levels. Rated for 120\/230 VAC at 15\/10 amps, this SPST switch is a direct OEM-style replacement. The blue color coding and 3-inch insert dimension allow for correct identification and positioning during service. Licensed HVAC technicians perform this replacement as part of routine furnace diagnostics and safety-system maintenance.\u003c\/p\u003e\u003cp\u003eThis limit switch is used in residential gas furnace applications where thermal overheat protection is required in the heat exchanger or plenum area. It is specifically listed for use on the R801PA075317MSA and R801PA075317MXA gas furnace models. The auto-reset design eliminates the need for manual reset after a single overheat event, though repeated tripping should prompt a full system diagnostic to identify the root cause before returning the unit to service.\u003c\/p\u003e\u003ch4\u003eKey Features\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003eOpens at 170 degrees F, closes at 150 degrees F for reliable overheat protection\u003c\/li\u003e\n\u003cli\u003eAuto-reset operation restores circuit continuity once temperatures normalize\u003c\/li\u003e\n\u003cli\u003eSPST, normally closed, 1-pole configuration for standard furnace limit circuits\u003c\/li\u003e\n\u003cli\u003eDual voltage rating: 120\/230 VAC at 15\/10 amps respectively\u003c\/li\u003e\n\u003cli\u003e3-inch insert dimension for correct fitment in the furnace heat exchanger collar\u003c\/li\u003e\n\u003cli\u003eBlue color coding aids identification and correct part matching during service\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eCompatibility\u003c\/h4\u003e\u003cp\u003eListed for use on the RUUD R801PA075317MSA and R801PA075317MXA gas furnace models.\u003c\/p\u003e\u003ch4\u003eInstallation Notes\u003c\/h4\u003e\u003cp\u003eInstallation should be performed by a licensed HVAC technician. Shut off all power to the furnace at the disconnect and turn off the gas supply before removing the existing switch. Verify the insert length and temperature ratings match before installing the replacement. Repeated limit trips after replacement indicate an airflow or heat exchanger issue that must be diagnosed before the system is returned to service.\u003c\/p\u003e\u003ch4\u003eTechnical Specifications\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSwitch Type\u003c\/strong\u003e: SPST, Normally Closed, Auto Reset, 1-Pole\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOpen Temperature\u003c\/strong\u003e: 170 degrees F\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eClose Temperature\u003c\/strong\u003e: 150 degrees F\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVoltage Rating\u003c\/strong\u003e: 120\/230 VAC\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAmperage Rating\u003c\/strong\u003e: 15\/10 amps\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInsert Length\u003c\/strong\u003e: 3 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eColor\u003c\/strong\u003e: Blue\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length\u003c\/strong\u003e: 5.45 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWidth\u003c\/strong\u003e: 3.05 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eHeight\u003c\/strong\u003e: 2.05 inches\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWeight\u003c\/strong\u003e: 0.08 pounds\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch4\u003eStandard Information\u003c\/h4\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBrand\u003c\/strong\u003e: RUUD\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eManufacturer Part Number\u003c\/strong\u003e: 47-104990-03\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"RUUD","offers":[{"title":"Default Title","offer_id":51284129579314,"sku":"47-104990-03","price":15.88,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0270\/4519\/9983\/files\/309277766.jpg?v=1781069309","url":"https:\/\/voomisupply.com\/products\/ruud-47-104990-03-gas-furnace-limit-switch-auto-reset","provider":"Voomi Supply","version":"1.0","type":"link"}