OEM Lennox High Pressure Switch — 55W64

The genuine OEM Lennox 55W64 high pressure switch protects your Lennox system by monitoring discharge-side refrigerant pressure and shutting down the compressor before it reaches damaging levels. Installed on the high-pressure line, it trips at a factory-specified setpoint when pressure spikes — a common result of a dirty condenser coil, a failed condenser fan motor, an overcharged system, or obstructed airflow — then resets once safe conditions return.

Common failure symptoms: A failing 55W64 can cause repeated high-pressure lockouts, a compressor that shuts off soon after starting, intermittent no-cool complaints, or a switch that will not reset. A shorted or stuck-closed switch eliminates overpressure protection and endangers the compressor.

Why OEM matters: Lennox calibrates the 55W64 to precise cut-out and reset pressures matched to your unit's compressor and coil design. Aftermarket substitutes often use incorrect thresholds that cause nuisance trips or fail to protect when it counts. Choosing the authentic OEM 55W64 ensures correct calibration, proper terminal fit, and dependable protection for your Lennox equipment.