Lennox 86M50 – LB-109423A Air Proving Switch Tubing Kit is a high-quality silicone rubber replacement tube designed to ensure accurate pressure sensing and reliable furnace performance. With a 3/16 inch inner diameter and 31-inch length, this tubing provides the ideal flexibility, heat resistance, and airtight seal necessary for proper operation of air proving and pressure switches in residential and light commercial HVAC systems.

Manufactured to Lennox OEM specifications, this black silicone tube is engineered for long-term durability and is commonly used during maintenance, troubleshooting, and switch replacement procedures. Ideal for restoring correct airflow verification and preventing burner or blower errors caused by cracked or deteriorated tubing.

 

Key Features:

• OEM Lennox LB-109423A replacement tubing
• Durable silicone rubber construction for heat and pressure resistance
• 3/16 inch ID for precise air switch fitment
• 31 inch length for flexible installation routing
• Helps restore accurate furnace air proving and safety control
• Suitable for a wide range of Lennox furnaces and HVAC systems

 

Specifications:

• Product Type: Air proving/pressure switch tubing
• OEM Part Number: 86M50
• Manufacturer Part Number: LB-109423A
• Material: Silicone rubber
• Inner Diameter (ID): 3/16 inch
• Length: 31 inches
• Color: Black
• Flexibility: High, suitable for tight routing
• Temperature Resistance: Designed for typical furnace cabinet operating ranges
• Compatibility: Fits Lennox furnace air proving and pressure switch assemblies requiring 3/16" ID tubing
• Application: Replacement tubing for maintaining proper airflow sensing and safety operation