Lennox 75M22 Pressure Switch

The Lennox 75M22 Pressure Switch is a high-precision OEM replacement part engineered for critical airflow monitoring in specific Lennox and Armstrong furnace models, including the G61MPV series. This dual pressure switch is factory-calibrated with settings of 0.50" and 0.75" WC, ensuring the combustion air inducer maintains the correct static pressure for safe ignition and continuous operation. As a single-pole single-throw (SPST) component, it functions as a primary safety limit, cutting the 24V control circuit if it detects a blocked vent or inducer motor failure. Its heavy-duty construction is designed to withstand the thermal stress of high-efficiency gas heat cycles, making it a reliable HVAC furnace pressure switch for professional contractors and technicians performing system maintenance. Using genuine Lennox parts like the 75M22 (also referenced as BA20147/B) ensures exact compatibility with the control board's diagnostic logic, preventing nuisance trips and ensuring peak equipment performance.

• Precision Calibration: Meets exact 0.50" and 0.75" WC specifications to ensure accurate draft sensing and optimal burner efficiency.
• Direct OEM Fit: Eliminates the need for field modifications, allowing for rapid replacement in Lennox G61MPV furnaces.
• Enhanced Safety: Provides a critical fail-safe by monitoring for inducer assembly malfunctions or flue obstructions.
• Industrial Durability: Constructed with high-grade materials to resist moisture and high temperatures within the burner compartment.

• How can I tell if my Lennox pressure switch is failing? If your furnace control board displays a 2 or 3-flash code and the inducer starts but the igniter fails to glow, the Lennox 75M22 0.50/.75 WC switch may be stuck open or failing to close.
• Is this switch compatible with high-altitude installations? While the 75M22 is used in various configurations, always cross-reference your specific model's rating plate to ensure these WC settings match your local elevation requirements.
• Can I use a universal pressure switch as a substitute? We recommend using the genuine Lennox 75M22 to ensure the SPST action and pressure setpoints align perfectly with the manufacturer's safety protocols.

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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.