{"product_id":"oem-goodman-200-f-primary-limit-switch-for-gmnt045-3b-b1370189","title":"OEM Goodman 200°F Primary Limit Switch for GMNT045-3B — B1370189","description":"\u003cp\u003eThe genuine OEM Goodman \u003cstrong\u003eB1370189 Primary Limit Switch\u003c\/strong\u003e is the main high-limit safety control for \u003cstrong\u003eGMNT045-3B\u003c\/strong\u003e and compatible Goodman and Amana gas furnaces. Positioned on the heat-exchanger side of the burner box, it continuously monitors supply-air temperature and interrupts the gas valve if the furnace overheats — preventing heat-exchanger damage and cracked components caused by insufficient airflow.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eTrip temperature:\u003c\/strong\u003e 200°F (auto-reset)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Normally closed, opens on temperature rise\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReset:\u003c\/strong\u003e Automatic\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMounting:\u003c\/strong\u003e Heat-exchanger \/ vestibule panel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e Goodman\/Amana GMNT045-3B and compatible furnaces\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Part #:\u003c\/strong\u003e B1370189\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOEM vs. Generic\u003c\/h3\u003e\u003cp\u003eBecause the primary limit governs the furnace's core overheat protection, matching the exact 200°F trip point is essential. OEM B1370189 is factory-calibrated and drops into the original bracket. Generic replacements with adjustable or approximate ratings can trip early (short-cycling) or too late (risking the heat exchanger). We strongly recommend OEM for this component.\u003c\/p\u003e\u003ch3\u003eInstallation\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eDifficulty: Easy (1\/5).\u003c\/strong\u003e About 15 minutes. Cut power, disconnect the two wire terminals, remove the mounting screws, install the new limit in the same orientation, and reconnect. Run a full heat cycle to verify the furnace reaches temperature and shuts down normally. If the primary limit keeps tripping, inspect airflow — dirty filters, closed registers, or a weak blower are the usual culprits.\u003c\/p\u003e","brand":"Goodman","offers":[{"title":"Default Title","offer_id":63058127913331,"sku":"GOODMAN-11627","price":21.95,"currency_code":"USD","in_stock":true}],"url":"https:\/\/nationalhvacparts.com\/products\/oem-goodman-200-f-primary-limit-switch-for-gmnt045-3b-b1370189","provider":"National HVAC Parts","version":"1.0","type":"link"}