121-461

This high-quality air pressure switch is a critical safety component designed for HVAC systems and gas-fired furnaces. Often referred to as an air-proving switch or draft inducer switch, its primary function is to monitor the pressure differential created by the inducer motor to ensure the exhaust system is venting correctly before allowing the heating cycle to proceed. This Single Pole Normally Open (SPNO) switch is precisely calibrated to activate at -.21 IWC (Inches of Water Column) on rise. If your furnace is experiencing ignition failure, short-cycling, or a lockout condition, a malfunctioning pressure switch is a common cause. Replacing a faulty switch helps restore reliable operation and ensures that your heating equipment operates safely by preventing the buildup of combustion gases.
Type: Air Pressure Switch
Size: Standard
Application: Used in forced-air furnaces, boilers, and HVAC heating units to detect proper inducer blower operation and exhaust pressure.
Specifications: Switch Logic: SPNO (Single Pole Normally Open); Setpoint: -.21 IWC on rise; Function: Air proving and safety limit control.