Lennox 34M76 Pressure Switch

The Lennox 34M76 Pressure Switch is a critical safety component designed for high-efficiency condensing gas furnaces. Engineered with an actuation set point of .86" WC (Water Column) and a reset point of 1.01" WC, this Single-Pole Single-Throw (SPST) switch ensures the inducer motor establishes a proper vacuum before the ignition sequence begins. Designed for a 1/4" barb connection, it provides a reliable pneumatic seal to prevent the furnace from firing under restricted venting or failed inducer conditions.

For field technicians, the Lennox 34M7601 is the identical upgraded replacement, maintaining exact electrical and pressure specifications. This OEM Lennox furnace pressure switch is built with a durable thermoplastic enclosure and features an integrated mounting bracket for quick installation in tight burner compartments. Whether you are troubleshooting a furnace pressure switch open code or performing preventative maintenance on Lennox LF24 series units, using genuine parts ensures the system operates within manufacturer-defined safety parameters.

• Precise Pressure Calibration: Factory-set at .86 inch WC to maintain strict safety standards for combustion airflow.
• Direct Cross-Reference: Fully compatible and identical to Lennox 34M7601, simplifying inventory and part identification.
• Secure Pneumatic Interface: Standard 1/4" barb connection ensures a leak-free fit with existing pressure switch tubing.
• System Protection: Prevents furnace operation during flue obstructions, inducer failure, or intake blockages.
• Durable SPST Design: Reliable electrical switching rated for high-cycle furnace applications.

• Can I use the 34M76 instead of the 34M7601? Yes, these part numbers are identical and interchangeable for all Lennox applications requiring a .86" WC set point.
• What causes a Lennox pressure switch to stay open? Common causes include a clogged vent pipe, a cracked pressure switch hose, water accumulation in the collector box, or a failing inducer motor.
• How do I test the Lennox 34M76? Using a manometer and a multimeter, verify that the switch closes when the vacuum reaches 0.86" WC and remains closed during the heating cycle.

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.