{"product_id":"oem-goodman-m4-primary-high-limit-switch-acss961205dnaa-20162907","title":"OEM Goodman M4 Primary High Limit Switch ACSS961205DNAA — 20162906","description":"\u003cp\u003eThe OEM Goodman \u003cstrong\u003e20162906 M4 primary limit switch\u003c\/strong\u003e is the main high-temperature safety control mounted on the heat-exchanger \/ supply-air section of Goodman and Amana furnaces, including the \u003cstrong\u003eACSS961205DNAA\u003c\/strong\u003e. It continuously monitors plenum temperature and opens the gas-valve circuit if airflow is lost or the furnace overheats — protecting the heat exchanger from cracking and preventing unsafe operation.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003ePart type: Primary high-limit switch (M4 series)\u003c\/li\u003e\n\u003cli\u003eOEM Part Number: 20162906\u003c\/li\u003e\n\u003cli\u003eAction: Normally closed, opens on over-temperature, auto-reset on cool-down\u003c\/li\u003e\n\u003cli\u003eMounting: Flange-mount to furnace bulkhead\u003c\/li\u003e\n\u003cli\u003eTerminals: 1\/4\" quick-connect spade\u003c\/li\u003e\n\u003cli\u003eFit: Direct OEM replacement\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eOEM vs. Generic\u003c\/h3\u003e\u003cp\u003eThe OEM M4 switch is matched to this furnace's exact trip temperature and mounting flange. Generic limits often differ in trip point or footprint, leading to short-cycling on limit or improper protection. For a primary safety control, use OEM.\u003c\/p\u003e\u003ch3\u003eInstallation Difficulty\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eModerate\u003c\/strong\u003e — Power down the furnace, remove the blower\/control door, disconnect the two leads, unscrew the flange, and install the replacement in the same orientation. Verify airflow and filter condition, which are common causes of limit trips.\u003c\/p\u003e","brand":"Goodman","offers":[{"title":"Default Title","offer_id":63057465016691,"sku":"GOODMAN-2432","price":14.95,"currency_code":"USD","in_stock":true}],"url":"https:\/\/nationalhvacparts.com\/products\/oem-goodman-m4-primary-high-limit-switch-acss961205dnaa-20162907","provider":"National HVAC Parts","version":"1.0","type":"link"}