Lennox 65W49 Pressure Switch

The Lennox 65W49 Pressure Switch is a critical safety component calibrated to -.60" WC (water column) for precise inducer motor monitoring and combustion air verification. As a genuine Lennox OEM replacement part, this SPST (Single Pole Single Throw) switch ensures seamless integration with furnace control boards, preventing ignition if proper venting pressure isn't maintained. Featuring a standard 1/4" barb connection, it offers a secure fit for vacuum tubing, eliminating potential air leaks that cause intermittent furnace lockout codes. This component serves as the direct Lennox 65W4901 and 100684-02 replacement, designed to handle the specific pneumatic requirements of high-efficiency gas furnaces. Field technicians specify the 65W49 over universal alternatives to avoid nuisance tripping and to maintain the factory-engineered safety sequence of the appliance. Its rugged construction is built to withstand the heat cycles and moisture common in secondary heat exchanger environments.

• Direct Fit Legacy Compatibility: Replaces obsolete part numbers 45694-002, FS6761-1560, and 65W4901 without bracket modification.
• Precise Calibration: Factory-set at -.60" WC to match original equipment design specs for reliable flue gas proving.
• Standardized Connectivity: Features a 1/4" barb and standard spade terminals for quick field installation and troubleshooting.
• Safety Compliance: Functions as a primary limit for Lennox HVAC systems, ensuring the combustion process only occurs under safe atmospheric conditions.

What are the symptoms of a failing Lennox 65W49 pressure switch?
Common signs include the inducer motor running continuously without the igniter glowing, or a specific flash code on the control board indicating the pressure switch failed to close or stayed open despite sufficient draft.

Can I use a universal pressure switch instead of the 65W49?
While universal switches exist, they often require manual calibration. Using this genuine Lennox 65W49 ensures the -.60" WC set point is exact, preventing dangerous rollout conditions or improper combustion cycles.

Is the 65W49 compatible with all Lennox furnaces?
No, it is specific to models requiring a -.60" WC rating. Always verify the pressure rating on the label of your existing switch before installation.

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.