{"product_id":"oem-lennox-flame-rollout-switch-52m74","title":"OEM Lennox Flame Rollout Switch — 52M74","description":"\u003cp\u003eThe Lennox \u003cstrong\u003e52M74\u003c\/strong\u003e flame rollout switch is a critical safety limit control installed on the burner assembly of your Lennox furnace. It continuously monitors for flames that escape or \"roll out\" of the burner box — a condition caused by blocked flue passages, cracked heat exchangers, or restricted combustion air. When abnormal heat is detected, the \u003cstrong\u003e52M74\u003c\/strong\u003e trips instantly and shuts off the gas valve, preventing dangerous overheating and fire hazards.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eCommon failure symptoms:\u003c\/strong\u003e If this switch fails or nuisance-trips, your furnace may lock out, refuse to fire, or start and then shut down after a few seconds. You may also see a rollout fault code on the control board or find the furnace running cold despite calling for heat. A tripped or defective switch should never be bypassed, as it is a life-safety component.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhy OEM matters:\u003c\/strong\u003e Genuine Lennox parts are calibrated to the exact trip temperature and mounting specification your furnace was engineered for. Aftermarket substitutes with the wrong reset temperature can nuisance-trip or, worse, fail to protect the unit. Installing the OEM \u003cstrong\u003e52M74\u003c\/strong\u003e guarantees correct fit, rated response, and full compatibility with your Lennox equipment.\u003c\/p\u003e","brand":"Lennox","offers":[{"title":"Default Title","offer_id":63081103556979,"sku":"LNX-52M74","price":19.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0984\/1190\/5395\/files\/nhvac-limit-switch-rollout-LNX-52M74.jpg?v=1783760974","url":"https:\/\/nationalhvacparts.com\/products\/oem-lennox-flame-rollout-switch-52m74","provider":"National HVAC Parts","version":"1.0","type":"link"}