OEM Lennox Dual Pressure Switch Assembly — 26W40

The genuine OEM Lennox 26W40 dual pressure switch assembly is a critical safety control that monitors both high-side and low-side refrigerant pressures in your Lennox air conditioning or heat pump system. When pressures move outside safe operating limits, the switch interrupts the compressor circuit to prevent catastrophic damage — protecting your compressor from overheating, liquid slugging, and loss-of-charge conditions.

Common failure symptoms: If the 26W40 fails or trips repeatedly, you may notice the compressor short-cycling, the outdoor unit refusing to start, nuisance lockouts on hot or cold days, or an open control circuit that leaves the system dead. Contacts can weld shut or fail open over years of thermal cycling, and the sensing diaphragm can lose calibration.

Why OEM matters: Lennox systems are engineered to precise pressure cut-out and cut-in setpoints. An aftermarket switch with slightly different trip thresholds can cause false lockouts or, worse, allow the compressor to run in a damaging condition. The factory 26W40 guarantees correct setpoints, fittings, and electrical ratings for a reliable, drop-in fit that restores your equipment's built-in protection.