{"product_id":"oem-lennox-fan-limit-thermostat-135-175-f-21p84","title":"OEM Lennox Fan\/Limit Thermostat 135-175°F — 21P84","description":"\u003cp\u003eThe genuine OEM Lennox \u003cstrong\u003e21P84\u003c\/strong\u003e is an adjustable fan and limit thermostat with a 135–175°F operating range and a 40°F differential. This dual-function control energizes the blower once the heat exchanger reaches temperature and acts as a high-limit safety switch, shutting off the burner if the furnace overheats. It protects your Lennox equipment while ensuring the fan only runs when there is usable heat to deliver.\u003c\/p\u003e\u003cp\u003eWhen a fan\/limit switch fails, you may experience a blower that runs constantly or never starts, short cycling on the high limit, cold air blowing at startup, or a furnace that shuts down on an overheat safety. A worn bimetal element or pitted contacts are common causes of these symptoms.\u003c\/p\u003e\u003cp\u003eChoosing the OEM Lennox \u003cstrong\u003e21P84\u003c\/strong\u003e guarantees the correct temperature range, differential, and mounting for Lennox furnaces. Because this is a safety-critical control, an incorrect or generic substitute can allow unsafe operation or nuisance shutdowns. The factory part delivers the precise calibration and reliable protection your Lennox system was engineered for.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081078620531,"sku":"LNX-21P84","price":19.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-limit-switch-snap-disc-LNX-21P84.jpg?v=1783760930","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-fan-limit-thermostat-135-175-f-21p84","provider":"National HVAC Parts","version":"1.0","type":"link"}