OEM Lennox Pressure Switch — 18M62

The genuine OEM Lennox 18M62 pressure switch is a critical safety component that confirms adequate venting airflow before your furnace's ignition sequence begins. It monitors the negative pressure created by the draft inducer and, if proper airflow is detected, closes to allow the ignition cycle to proceed. Designed as a direct factory replacement, the 18M62 is engineered to the exact pressure tolerances your Lennox furnace requires for safe, reliable operation.

Common Failure Symptoms

• Furnace ignites briefly then shuts down on a lockout code
• No ignition at all with the inducer running
• Repeated short-cycling during a heating call
• Control board reporting a pressure switch fault

A stuck or failed pressure switch is a common cause of no-heat calls, since the furnace will refuse to fire when it cannot verify safe venting.

Why OEM Matters

Aftermarket switches are often calibrated to generic set points that may not match your unit's specifications, leading to nuisance lockouts or, worse, bypassing a vital safety function. The OEM Lennox 18M62 is factory-matched to the correct actuation pressure, ensuring proper fit, dependable safety operation, and the longevity you expect from your Lennox equipment.