Lochinvar & A.O. Smith 100109814 Pressure Switch

The Lochinvar & A.O. Smith 100109814 Pressure Switch is the direct performance-validated replacement for the legacy 180997-1 component. This critical safety device is engineered for HVAC inducer motor blowers and water heater venting systems, featuring a precise 2.5" W.C. (Water Column) trip point. Designed to monitor differential pressure, this OEM pressure switch ensures the combustion fan is moving sufficient air before enabling the ignition sequence. The 100109814 is commonly utilized in high-efficiency commercial and residential water heaters, providing reliable contact closure in high-demand environments. Its robust diaphragm design handles back-pressure fluctuations, preventing nuisance lockouts while maintaining strict safety standards. For contractors, this Lochinvar replacement part offers seamless mechanical fitment and electrical continuity, ensuring the appliance operates within specified draft parameters. When troubleshooting pressure switch stuck open errors, verifying the exact water heater pressure switch set point is essential for restoring system performance and safety.

Key Benefits

• Factory-Calibrated Set Point: Features a fixed 2.5 inch WC rating to meet strict manufacturer draft requirements.
• Direct OEM Replacement: Serves as the official update for the 180997-1, ensuring exact mounting and wiring compatibility.
• Enhanced Safety Logic: Prevents burner operation if intake or exhaust flow is restricted, protecting heat exchangers.
• High-Durability Housing: Built to withstand the thermal stress and vibration found in modern inducer assemblies.
• Standard Terminal Connections: Utilizes universal spade connectors for rapid field installation and testing.

Common Questions

What causes a pressure switch error on Lochinvar units?
Most errors result from obstructed venting, a failing inducer motor, or a ruptured diaphragm within the 100109814 switch itself.

Can I use a 100109814 to replace a switch with a different WC rating?
No. Using a switch with an incorrect water column rating can lead to hazardous combustion conditions or frequent system failures.

How do I verify if my 180997-1 is faulty?
Technicians should use a manometer to verify the draft pressure against the 2.5" rating and a multimeter to check for continuity crossing the terminals during inducer startup.

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.