OEM Lennox Dual Pressure Switch Assembly — 63W40

The genuine OEM Lennox 63W40 dual pressure switch assembly is a critical safety component that monitors both the high-side and low-side refrigerant pressures in your Lennox HVAC system. When pressures move outside of safe operating limits — whether from a refrigerant leak, a dirty coil, a failing compressor, or a blocked line — the switch opens and shuts down the compressor to prevent catastrophic damage. This assembly combines both the high-pressure and low-pressure functions into a single, factory-calibrated unit designed to protect your equipment and your investment.

Common failure symptoms include a system that trips off intermittently, a compressor that will not start, nuisance lockouts on control boards, or an outdoor unit that runs only briefly before cutting out. A pressure switch stuck open will prevent operation entirely, while one stuck closed removes an essential layer of protection from your system.

Why OEM matters: Lennox pressure switches are calibrated to specific cut-out and cut-in pressures matched to your unit's refrigerant charge and design. Generic aftermarket switches often trip at the wrong thresholds, causing false shutdowns or — worse — failing to protect the compressor. Installing the authentic Lennox 63W40 guarantees correct calibration, proper fit, and full compatibility with your system.