The Lennox 11U66 104371-03 Pressure Switch is a reliable OEM control component designed for accurate air pressure monitoring in residential and commercial HVAC systems. This pressure switch actuates at 0.55" W.C. (water column), ensuring precise detection of airflow and combustion air pressure changes. Engineered to meet Lennox original equipment specifications, the 11U66 pressure switch delivers consistent performance and long service life, making it ideal for furnace and air handler applications.

Perfect for HVAC technicians and contractors, this pressure switch helps maintain safe operation by signaling the control board when proper airflow or vent pressure conditions are achieved. The durable construction and compatibility with a wide range of Lennox heating systems reduce downtime and improve system reliability. Whether you’re replacing a worn switch or stocking essential service parts, the 104371-03 pressure switch offers dependable performance and OEM quality.

 

Key Features:

• OEM Lennox pressure switch designed for accurate air pressure monitoring and system safety.
• Actuation at 0.55" W.C. ensures precise control board signaling under correct airflow or vent pressure.
• Durable build for reliable performance in residential and light commercial HVAC systems.
• Direct replacement for Lennox part number 11U66 / 104371-03.
• Essential service part for furnaces, air handlers, and other pressurized HVAC applications.

 

Applications:

Used in Lennox HVAC equipment to monitor negative and positive pressure changes in ventilation and combustion systems, triggering proper operation of blowers and gas valves based on airflow conditions.

 

Specifications:

• Lennox Part Number: 11U66
• Manufacturer Part Number: 104371-03
• Pressure Actuation: 0.55" W.C.
• Function: Air/Combustion Pressure Detection