Lennox 29M17 Limit Switch R-407C utilizing the same 1k ohm

utilizing the same 1k ohm platinum curves to ensure full backward compatibility with your existing Johnson Controls setup

and 5L profiles

or visible gaps at the seams

As a direct replacement for FR1400U-108

Common indicators include the furnace blower running without ignition or the control board flashing a specific pressure switch lockout code

Lennox 29M17 Limit Switch R-407C utilizing the same 1k ohmWhen you're troubleshooting a furnace that's short cycling or throwing a four flash diagnostic code, the Lennox 29M17 Limit Switch is often the first component to inspect. As a critical OEM replacement part, this L215 40F limit switch is engineered to protect the heat exchanger from thermal stress. It features a fixed setpoint that opens the electrical circuit at 215F and automatically resets once the temperature drops to 40F, ensuring the HVAC system