Lochinvar & A.O. Smith 100233301 – 1.25″ WC N.O. Air Pressure Switch

Description

Product Overview

The Lochinvar & A.O. Smith 100233301 is an OEM replacement normally open (N.O.) air pressure switch engineered to deliver reliable combustion safety control in Lochinvar and A.O. Smith heating equipment. Rated at -1.25″ WC (water column), this switch monitors draft inducer and combustion air pressure to confirm proper airflow before allowing ignition — a critical safeguard against unsafe operating conditions.

Key Features

• OEM replacement part for Lochinvar and A.O. Smith heating systems
• Normally open (N.O.) configuration — closes upon sensing adequate negative pressure
• Set point: -1.25″ WC (water column)
• Monitors combustion air and draft inducer pressure for safe ignition sequencing
• Helps prevent ignition under inadequate or blocked flue/air conditions
• Direct OEM replacement ensures proper fit and reliable operation

Application

Designed for use in Lochinvar and A.O. Smith residential and commercial water heaters and boilers, this air pressure switch is a key component of the burner safety circuit. It verifies that the draft inducer is operating at the correct pressure differential before the control board allows the ignition sequence to proceed, protecting the appliance and occupants from hazardous combustion conditions.

Specifications

• SKU: 100233301
• Brand: Lochinvar & A.O. Smith
• Switch Type: Air Pressure Switch
• Contact Configuration: Normally Open (N.O.)
• Set Point: -1.25″ WC (water column)