Lennox 14A57 Gas Furnace Pressure Switch 2-stage 95AF2V

Product Description

The LENNOX 14A57 is a 2-stage pressure switch designed for use in gas furnace applications. It monitors draft inducer operation by sensing negative pressure in the flue or combustion air proving circuit, preventing ignition or gas valve operation if proper airflow is not confirmed. This switch is rated at 0.8/0.5 inches WC, corresponding to its two-stage set points, and serves as a critical safety component in high-efficiency condensing furnace systems. Installation is typically performed by a licensed HVAC technician as part of a scheduled maintenance replacement or diagnostic service call.

This pressure switch is used on the LENNOX 95AF2V gas furnace, a two-stage, high-efficiency residential condensing furnace. It fits within the low-voltage control circuit and works in conjunction with the draft inducer motor and control board to verify proper venting before allowing the heating sequence to proceed. The dual set points correspond to the low-fire and high-fire stages of the two-stage gas valve operation.

Key Features

• Dual set points at 0.8 inches WC and 0.5 inches WC for two-stage furnace operation
• Functions as a safety interlock to confirm draft inducer airflow before ignition
• Designed for use in high-efficiency condensing gas furnace control circuits
• OEM-style replacement for the LENNOX 95AF2V gas furnace

Compatibility

Designed for use on the LENNOX 95AF2V gas furnace as stated by the manufacturer.

Installation Notes

This part is installed by a licensed HVAC technician. Before servicing, shut off electrical power to the furnace at the disconnect switch or breaker and allow the system to cool. Verify the replacement switch set points match the original before installation, and inspect the rubber tubing and hose barbs for cracks or blockages during the swap. Follow all applicable local codes and the furnace manufacturer installation instructions.

Technical Specifications

• Type: Pressure Switch, 2-Stage
• Set Points: 0.8 / 0.5 inches WC
• Used On: 95AF2V Gas Furnace
• Weight: 1.0 pounds

Standard Information

• Brand: LENNOX
• Manufacturer Part Number: 14A57