{"product_id":"oem-goodman-m4-primary-limit-switch-for-amh80704bxca-20162906","title":"OEM Goodman M4 Primary Limit Switch for AMH80704BXCA — 20162906","description":"\u003cp\u003eThe \u003cstrong\u003eGoodman 20162906 M4 Primary Limit Switch\u003c\/strong\u003e is a genuine OEM high-limit safety control for the \u003cstrong\u003eAMH80704BXCA\u003c\/strong\u003e gas furnace and compatible Goodman and Amana models. Mounted on the heat exchanger bulkhead, this primary limit monitors supply-air temperature and de-energizes the gas valve if the furnace overheats — typically caused by a dirty filter, blocked ductwork, or a failed blower. As an \u003cstrong\u003eauto-reset\u003c\/strong\u003e control, it closes again once temperatures normalize, cycling the furnace to protect the heat exchanger from thermal stress and cracking.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eType: Primary high-limit switch (M4 series)\u003c\/li\u003e\n\u003cli\u003eConfiguration: Normally closed, automatic reset\u003c\/li\u003e\n\u003cli\u003eFunction: Opens gas valve circuit on overheat\u003c\/li\u003e\n\u003cli\u003eTerminals: 1\/4 in. quick-connect spade\u003c\/li\u003e\n\u003cli\u003eOEM Part Number: 20162906\u003c\/li\u003e\n\u003cli\u003eFits: Goodman \/ Amana AMH80704BXCA and related 80% gas furnaces\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOEM vs. Generic\u003c\/h3\u003e\u003cp\u003eThe OEM 20162906 is factory-calibrated to the exact cut-out temperature and mounting geometry Goodman specifies for this furnace. Universal limit switches often differ in trip point or bracket depth, which can cause short-cycling on heat or fail to protect the heat exchanger. For a primary safety device, the genuine OEM part is the correct choice.\u003c\/p\u003e\u003ch3\u003eInstall Difficulty\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eEasy (2\/5).\u003c\/strong\u003e Cut power at the disconnect, unplug the two spade terminals, remove the two mounting screws, and install the new switch in the identical position and orientation. Allow 10–15 minutes. If the limit continues to trip, address the underlying airflow problem — replace the filter and confirm blower operation — rather than repeatedly replacing the switch.\u003c\/p\u003e","brand":"Goodman","offers":[{"title":"Default Title","offer_id":63057613783411,"sku":"GOODMAN-5387","price":34.95,"currency_code":"USD","in_stock":true}],"url":"https:\/\/nationalhvacparts.com\/products\/oem-goodman-m4-primary-limit-switch-for-amh80704bxca-20162906","provider":"National HVAC Parts","version":"1.0","type":"link"}