Lochinvar & A.O. Smith 100166249 Pressure Switch

The Lochinvar & A.O. Smith 100166249 Pressure Switch is a critical safety component designed for high-efficiency condensing boilers and water heaters. As a direct replacement for the obsolete PRS30030, this genuine OEM pressure switch ensures your equipment maintains proper combustion air proving and flue monitoring. Featuring a 1.05" WC setpoint and a SPDT (Single-Pole Double-Throw) configuration, this switch provides the reliable electrical switching necessary to signal the control board during the inducer motor's pre-purge and run cycles. Reliability in this part is non-negotiable; a drifting setpoint or sticking contacts often leads to common boiler ignition failure or intermittent error codes regarding airflow. This switch is built to strict HVAC pressure sensor specifications, ensuring it handles the precise micro-pressure differentials found in Lochinvar Knight and A.O. Smith commercial units. Installing this 100166249 boiler part restores the system's ability to safely verify venting integrity before allowing the gas valve to open, protecting the heat exchanger from improper combustion conditions.

• Direct OEM Compatibility: Engineered as the exact replacement for the Lochinvar PRS30030 to ensure seamless fit and electrical integration.
• Precise Pressure Calibrations: Factory-set at 1.05" WC for accurate sensing of flue gas pressure and combustion air delivery.
• Durable SPDT Switch Design: The Single-Pole Double-Throw contact arrangement offers versatile wiring for various control board safety loops.
• System Safety Assurance: Prevents burner operation if the draft inducer fails or if the venting system becomes obstructed.
• Rugged Construction: Built to withstand the humidity and temperature fluctuations typical within a high-efficiency condensing boiler cabinet.

How do I know if my Lochinvar pressure switch is failing?
Common symptoms include the inducer motor running continuously without the boiler firing, or receiving a "Pressure Switch Did Not Close" error code on the LCD display. You can verify the switch by checking for continuity across the terminals once the inducer reaches full speed, ensuring the 1.05" WC threshold is met.

Is the 100166249 compatible with the older PRS30030?
Yes, the 100166249 is the current manufacturer-approved replacement part for the PRS30030. No modifications to the mounting bracket or tubing are required for installation.

What causes a pressure switch to stay open?
Outside of a mechanical failure of the switch itself, blocked vent pipes, a failing inducer motor, or moisture/debris in the sensing tubing can prevent the pressure switch from closing. Always inspect the silicone tubing for cracks or water buildup during replacement.

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.