Ao Smith 100209984 Air Pressure Switch Kit 0.32 in Wc

Product Description

The AO SMITH 100209984 is a normally open air pressure switch kit designed for use in gas-fired water heater and boiler venting systems. Air pressure switches monitor flue draft or combustion air flow and interrupt the control circuit when adequate airflow is not detected, providing a critical safety interlock. This kit is rated at a setpoint of 0.32 inches water column (WC) and ships as a complete kit with the hardware needed for installation. It is typically installed by licensed plumbers, HVAC technicians, or water heater service professionals.

This switch kit is suited for residential and light commercial gas water heater applications where draft-proving or combustion-air-proving is required by the appliance control sequence. The normally open configuration means the switch contacts close when sufficient negative pressure is established in the flue or combustion air passage, allowing the burner sequence to proceed. Installation is typically required when the original switch has failed, reads out of spec, or is being replaced as part of a flue system service.

Key Features

• Normally open (N.O.) contact configuration closes on adequate draft or airflow detection
• Setpoint of 0.32 inches water column (WC) for precise pressure proving
• Kit format includes associated hardware for a complete swap-out
• Provides a safety interlock to prevent burner operation without confirmed airflow
• Direct replacement format for straightforward serviceability

Compatibility

Designed as an OEM-style replacement air pressure switch kit for AO SMITH gas-fired water heater and boiler models requiring a normally open 0.32 inches WC pressure switch.

Installation Notes

Installation should be performed by a licensed plumber or qualified HVAC technician familiar with gas appliance venting and control systems. Shut off gas supply and disconnect power to the appliance before beginning any work on the pressure switch or wiring connections. Ensure all pneumatic tubing connections to the switch ports are secure and free of cracks or blockages before restoring operation. Work should comply with applicable local codes and the appliance manufacturer installation instructions.

Technical Specifications

• Contact Configuration: Normally Open (N.O.)
• Setpoint: 0.32 inches WC
• Part Format: Kit

Standard Information

• Brand: AO SMITH
• Manufacturer Part Number: 100209984