The Lennox 56M93 (BA20133/B) Pressure Switch is an OEM safety control designed to monitor and verify proper draft and airflow in compatible Lennox heating systems. This factory-specified replacement ensures reliable furnace operation by confirming that the inducer motor is creating the correct negative pressure before ignition. If unsafe or incorrect airflow conditions occur, the switch interrupts the heating cycle to protect the system.

Built to Lennox’s performance standards, the BA20133/B pressure switch offers dependable operation, accurate sensing, and long-term durability. It is commonly used in residential and light commercial Lennox gas furnaces that require precise airflow verification for safe combustion.

This part is ideal for HVAC technicians, contractors, and homeowners who need an authentic Lennox control component to restore proper furnace safety functions, eliminate error codes, or address issues related to draft and venting performance.

 

Key Features:

 

• Genuine Lennox OEM pressure switch for accurate airflow verification
• Ensures safe system startup by confirming inducer draft
• Helps prevent ignition failures and pressure-related furnace shutdowns
• Designed for long-term durability and consistent sensing performance
• Direct-fit replacement for Lennox models requiring BA20133/B

 

Technical Specifications:

 

• Part Number: 56M93
• Manufacturer Number: BA20133/B
• Component Type: Furnace pressure switch
• Application: Draft/airflow safety verification
• Compatibility: Select Lennox gas furnace models (technicians should confirm model application)