{"product_id":"tempstar-safety-limit-thermostat-for-tnls2025hde-oem-51302031100-ships-today","title":"Tempstar Safety Limit Thermostat for TNLS2025HDE — OEM 51302031100 | Ships Today","description":"\u003ch3\u003eOverview\u003c\/h3\u003e\u003cp\u003eThis is the genuine OEM safety limit thermostat (part number 51302031100) for the Tempstar TNLS2025HDE. This safety thermostat is a temperature-sensing limit switch that protects the system by opening the control circuit if it detects an over-temperature condition — for example, restricted airflow or auxiliary\/strip-heat overheating. When the safety thermostat fails open, the unit will not energize heat; when it fails closed or drifts out of calibration, it no longer provides over-temperature protection. Replacing a faulty safety limit restores both reliable operation and the built-in protection the system depends on.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003eSpec\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003e51302031100\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDescription\u003c\/td\u003e\n\u003ctd\u003eThermostat, Safety (TSTAT Safety)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eType\u003c\/td\u003e\n\u003ctd\u003eSafety Limit \/ High-Limit Switch\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eBrand\u003c\/td\u003e\n\u003ctd\u003eTempstar (ICP \/ Heil)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFitment\u003c\/td\u003e\n\u003ctd\u003eOEM Replacement\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eFunction\u003c\/td\u003e\n\u003ctd\u003eOver-Temperature Protection\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eDirect-fit OEM replacement for the Tempstar TNLS2025HDE and related ICP \/ Heil \/ Comfortmaker units that use this safety limit thermostat. Match the part number on your existing switch to confirm fitment.\u003c\/p\u003e\u003ch3\u003eInstallation Guide\u003c\/h3\u003e\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eSafety First\u003c\/strong\u003e — Disconnect power and verify zero voltage with a multimeter.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAccess\u003c\/strong\u003e — Remove the service panel to reach the safety thermostat.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDocument\u003c\/strong\u003e — Photograph the wiring and mounting position before disconnecting.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRemove\u003c\/strong\u003e — Disconnect the leads and unfasten the old safety thermostat from its bracket\/surface.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eInstall\u003c\/strong\u003e — Mount the new safety thermostat in the same location and reconnect the leads per your photo.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTest\u003c\/strong\u003e — Restore power and verify the system energizes and cycles normally without nuisance trips.\u003c\/li\u003e\n\u003c\/ol\u003e\u003ch3\u003eSigns You Need a Replacement\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eNo heat or intermittent heat operation\u003c\/li\u003e\n\u003cli\u003eNuisance high-limit trips or short cycling\u003c\/li\u003e\n\u003cli\u003eOpen\/failed reading across the switch on a multimeter\u003c\/li\u003e\n\u003cli\u003eBurned or discolored terminals on the safety thermostat\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eShipping \u0026amp; Returns\u003c\/h3\u003e\u003cp\u003eShips same day before 3 PM CST. 30-day returns. Backed by the National HVAC Parts fitment guarantee.\u003c\/p\u003e","brand":"Tempstar","offers":[{"title":"Direct Replacement","offer_id":63021633405299,"sku":"51302031100-GEN","price":34.95,"currency_code":"USD","in_stock":true},{"title":"OEM","offer_id":63048487633267,"sku":"51302031100","price":45.44,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-limit-switch-snap-disc-51302031100.jpg?v=1782961319","url":"https:\/\/nationalhvacparts.com\/products\/tempstar-safety-limit-thermostat-for-tnls2025hde-oem-51302031100-ships-today","provider":"National HVAC Parts","version":"1.0","type":"link"}