OEM Lennox Furnace Limit Switch — 49L88

The genuine OEM Lennox 49L88 limit switch is a critical over-temperature safety device that prevents your furnace from overheating. Positioned to sense heat at the heat exchanger or supply plenum, it opens the burner circuit whenever air temperature climbs above its rated setpoint. This protects the heat exchanger from cracking and shields your home from unsafe operating conditions caused by poor airflow or blower failure.

Common failure symptoms: The furnace cycles off before reaching temperature, repeated tripping on high limit, no heat with the blower running continuously, or a control board flashing an open-limit code. A worn or permanently open limit switch is a frequent cause of these nuisance shutdowns and no-heat service calls.

Why OEM matters: Each Lennox limit switch is calibrated to a precise cut-out temperature engineered for the furnace's specific airflow and heat exchanger design. Generic replacements with incorrect setpoints can permit overheating or cause frustrating false trips. The OEM 49L88 delivers the exact factory calibration, terminals, and mounting geometry your Lennox equipment requires.