Lennox 80K25 Pressure Switch

The Lennox 80K25 Pressure Switch is a critical safety component designed for precise combustion air pressure monitoring in Lennox, Armstrong, and Ducane furnace systems. This genuine OEM replacement part, also identified as 80K2501 or Honeywell IS20407-5896, features a fixed set point of .24" WC (Water Column). Engineered with a Single Pole Single Throw (SPST) contact configuration, it ensures the inducer motor is moving sufficient air before allowing the ignition sequence to proceed, preventing hazardous operation. The 1/4" barb connection allows for a secure, airtight fit to standard pressure switch tubing, maintaining the differential pressure integrity required for modern high-efficiency HVAC equipment. Built with a corrosion-resistant housing and a high-tolerance diaphragm, the 80K25 furnace pressure switch provides the reliable switching performance that veteran technicians expect when troubleshooting pressure switch stuck open or closed fault codes. Verified compatibility includes a wide range of G24M series and other 80% and 90% AFUE residential units.

Key Benefits

• OEM Accuracy: Factory-calibrated to .24 inches water column for exact safety compliance with original equipment manufacturer specifications.
• Direct Interchangeability: This unit is a direct replacement for Lennox 80K2501 and Honeywell PPS10052-2383, ensuring zero-mod installation.
• Robust Construction: Features a durable, corrosion-resistant housing designed to withstand the high-heat and moisture cycles of a furnace cabinet.
• Technical Standard: Standard 1/4" barb connection and SPST contacts integrate seamlessly with existing wiring harnesses and pneumatic lines.

Common Questions

What causes a .24" WC pressure switch to stay open?
Beyond a faulty switch, technicians should check for a clogged inducer port, cracked tubing, or a blocked flue vent. If the inducer motor isn't pulling enough draft to hit the .24" WC threshold, the SPST circuit will remain open as a safety precaution.

Can I use an 80K25 to replace a switch with a different set point?
No. Pressure switches are safety devices specifically tuned to the furnace's venting and combustion requirements. Installing a switch with a different Water Column rating can result in incomplete combustion or dangerous operating conditions.

How do I verify the 80K25 logic during troubleshooting?
Check for continuity across the terminals when the inducer is at full speed; the 80K25 should close its circuit at .24" WC. If the switch fails to close despite reaching proper vacuum levels, the internal diaphragm or SPST contacts have likely failed.

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.