Lennox 51W91 Pressure Switch necessitating a partial drain of

necessitating a partial drain of the isolated circuit

The sensor is constructed with a stainless steel bulb and a 9 3/4-inch PVC cable

Professional field technicians understand that a durable housing is non-negotiable for maintaining the calibration and integrity of pneumatic control systems

Measuring approximately 18-1/2 inches by 2-1/4 inches with a 1/8-inch thickness

Common Questions How do I resolve a 'Pressure Switch Open' error on a Lennox furnace

Lennox 51W91 Pressure Switch necessitating a partial drain ofThe Lennox 51W91 Pressure Switch is a critical safety component engineered for precision in Lennox gas furnace repair and maintenance. As an authentic OEM HVAC replacement part, this SPST pressure switch is calibrated to a specific set point of 0. 95" WC (water column), ensuring the inducer motor is drafting correctly before allowing the ignition sequence to proceed. Professionals recognize the Lennox 51W91 as the 56M05 direct replacement, maintaining