Ao Smith 100109962 Blower Prover Switch

Product Description

The AO SMITH 100109962 is a blower prover switch designed for use in gas water heater systems. This pressure-sensing switch monitors airflow from the combustion blower and sends a signal to the control board confirming that adequate draft is present before allowing the burner to fire. It is a safety-critical component that prevents ignition under unsafe venting conditions. Licensed plumbers and HVAC technicians are the primary installers of this switch during routine service calls or fault-code diagnostics on AO SMITH water heating equipment.

This blower prover switch is typically installed in residential gas water heater applications where a powered combustion blower is part of the flue or draft system. It is wired into the low-voltage control circuit and operates as a proving interlock that must close before ignition can proceed. Replacement is commonly required when the unit logs a pressure switch fault code or when the switch fails an open-circuit continuity test during troubleshooting.

Key Features

• Proves combustion blower operation before allowing burner ignition
• Integrates into the low-voltage safety control circuit
• OEM replacement part for AO SMITH gas water heater systems
• Designed to maintain safe draft and venting verification

Compatibility

Designed as an OEM-style replacement blower prover switch for AO SMITH gas water heaters equipped with a powered combustion blower assembly.

Installation Notes

Installation should be performed by a licensed plumber or qualified HVAC technician familiar with gas appliance controls. Shut off gas supply and disconnect power to the water heater before removing any components. Inspect the pressure port tubing for cracks or blockages before installing the new switch, as tubing faults can cause repeat failures. Work should comply with applicable local codes and the appliance manufacturer's service documentation.

Technical Specifications

• Component Type: Blower Prover Switch

Standard Information

• Brand: AO SMITH
• Manufacturer Part Number: 100109962