{"product_id":"oem-goodman-m4-primary-limit-switch-for-wfm18090s5cxcc-20162906","title":"OEM Goodman M4 Primary Limit Switch for WFM18090S5CXCC — 20162906","description":"\u003cp\u003eThe \u003cstrong\u003eGoodman 20162906 M4 Primary Limit Switch\u003c\/strong\u003e is a genuine OEM temperature control for the \u003cstrong\u003eWFM18090S5CXCC\u003c\/strong\u003e gas furnace and compatible Goodman\/Amana units. Mounted on the heat exchanger or blower deck, the primary limit continuously monitors supply-air temperature. If airflow drops or the furnace overheats, the switch opens to cut the burners and protect the heat exchanger, then automatically re-closes once temperatures return to a safe range.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003ePart Number:\u003c\/strong\u003e 20162906\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSeries:\u003c\/strong\u003e M4 primary limit\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Automatic-reset high-limit switch\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eContacts:\u003c\/strong\u003e Normally closed (opens on over-temperature)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFunction:\u003c\/strong\u003e Primary overheat\/airflow safety protection\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e WFM18090S5CXCC and related Goodman furnaces\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOEM vs. Generic\u003c\/h3\u003e\u003cp\u003ePrimary limits are matched to the furnace's specific trip temperature and mounting footprint. This OEM 20162906 M4 switch delivers the factory-calibrated open point, avoiding both nuisance short-cycling and unsafe late trips. Generic substitutes often differ in set point or bracket shape. For reliable protection, OEM is recommended.\u003c\/p\u003e\u003ch3\u003eInstall Difficulty\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eEasy.\u003c\/strong\u003e A common quarter-turn or two-screw mounted switch with spade terminals. Shut off power and gas, photograph the wiring, remove the old limit, and install the replacement in the same orientation. Roughly 15–20 minutes. Persistent tripping indicates an airflow problem worth a professional check.\u003c\/p\u003e\u003cp\u003eDo not jumper or defeat the primary limit — it safeguards the heat exchanger.\u003c\/p\u003e","brand":"Goodman","offers":[{"title":"Default Title","offer_id":63058227659123,"sku":"GOODMAN-14128","price":29.95,"currency_code":"USD","in_stock":true}],"url":"https:\/\/nationalhvacparts.com\/products\/oem-goodman-m4-primary-limit-switch-for-wfm18090s5cxcc-20162906","provider":"National HVAC Parts","version":"1.0","type":"link"}