ensuring a gas-tight seal that prevents coolant seepage and combustion gas leakage

Leak-Proof Connections: Features precision-machined 1/4" SAE flare fittings for a secure

provided the supply wiring is sized correctly for the total unit load

the unit maintains a significant 7

the coil is removable

Lennox 57M66 Pressure Switch 340793-762 ensuring a gas-tight seal thatThe Lennox 57M66 Pressure Switch is a critical safety component designed for precise combustion air proving in high efficiency gas furnaces. Factory calibrated to actuate at 1. 41" WC, this Single Pole Single Throw (SPST) switch ensures the inducer motor is generating sufficient static pressure to vent flue gases safely before allowing the ignition sequence to proceed. As a genuine OEM replacement part, it maintains the exact specifications required