IMAGE COMING SOON
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The Lennox 12P55 (OEM part number 102857-09) is a genuine OEM main high-limit control switch rated at 190°F, serving as the primary overheat protection device in compatible Lennox furnaces by cutting power to the burner when the heat exchanger temperature becomes unsafe. A malfunctioning main limit control can cause symptoms such as the furnace shutting down mid-cycle, failing to ignite, or the fan running without heat production. This direct OEM replacement delivers the precise trip temperature and fit required for reliable, safe Lennox furnace performance.