Lennox 20J97 Pressure Switch

The Lennox 20J97 Pressure Switch is a mission-critical safety component engineered for high-efficiency HVAC units requiring precise draft proving. This OEM Lennox replacement part features a 1.15" WC set point and a Single-Pole Single-Throw (SPST) configuration, ensuring the combustion air inducer is generating the necessary static pressure before allowing the ignition sequence to proceed. Designed with a standard 1/4" barb connection, it integrates seamlessly into the vacuum lines of compatible gas furnaces and air handlers to monitor for flue obstructions or inducer motor failure.

Built for the rigors of commercial and residential mechanical rooms, the Lennox 20J97 handles electrical loads up to 15A at 125/250VAC. The 1.15 inch water column switch is calibrated to strict tolerances to prevent nuisance tripping while providing reliable lockout protection against dangerous back-drafting conditions. For veteran contractors, this furnace pressure switch represents a direct-drop solution for restoring system safety and peak operational performance in equipment specified for a 1.15" WC threshold.

• Precise 1.15" WC Calibration: Ensures the system only fires when the inducer motor achieves the exact static pressure required for safe combustion.
• Durable SPST Construction: Designed for high-cycle reliability in demanding HVACR environments.
• Universal 1/4" Barb: Simplifies installation by matching standard pneumatic tubing used in most Lennox and Allied Air configurations.
• Safety Lockout Integration: Proactively prevents ignition if flue blockages or mechanical failures are detected in the venting system.

What are the symptoms of a failing Lennox 20J97 switch?
Common indicators include the inducer motor running continuously without the burners igniting, or the control board flashing a "Pressure Switch Open" fault code. Always verify the vacuum tubing is clear of moisture before condemning the switch.

Can I use a pressure switch with a different WC rating?
No. Pressure switches must match the manufacturer’s specified set point exactly. Installing a switch with a different rating, such as 0.90" or 1.50" WC, can lead to dangerous operating conditions or constant system lockouts.

Does this switch handle high-voltage circuits?
Yes, it is rated for up to 15A at 125/250VAC, making it suitable for a variety of pilot duty and motor control applications within the specified pressure range.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.