Lennox 11W10 Piston Kit

The Lennox 11W10 Piston Kit is a precision-engineered refrigerant metering device essential for maintaining the thermal efficiency of residential and light commercial cooling systems. This OEM Lennox part, also identified by part number 100484-38, features a 0.091 orifice size specifically calibrated to regulate the flow of refrigerant into the evaporator coil. For contractors performing a metering device replacement, this kit ensures the system operates within peak AHRI-certified parameters, preventing the common issues of liquid slugging or evaporator starve-out that occur with mismatched pistons. The 11W10 piston orifice is compatible with a wide range of Lennox, Armstrong, and Ducane air conditioning units and heat pumps. Utilizing genuine HVAC replacement parts like the 11W10 ensures the flow check assembly maintains consistent pressure drops across the liquid line, optimizing the seasonal energy efficiency ratio (SEER) of the entire split system.

Key Benefits

• Precise Flow Control: The 0.091" fixed orifice provides accurate refrigerant dosing for specific tonnage requirements.
• System Compatibility: Engineered as a direct replacement for Lennox 11W10, Armstrong, and Ducane evaporator coils.
• Durable Construction: High-grade brass and steel components resist corrosion and withstand high-pressure fluctuations.
• Performance Optimization: Restores factory-spec cooling capacity by ensuring the correct refrigerant metering rate.

Common Questions

What is the orifice size of the Lennox 11W10?

The 11W10 kit features a precision-machined 0.091-inch orifice, often referred to by technicians as a No. 91 piston.

Does this piston kit work with both AC and Heat Pump systems?

Yes, this flow check piston is designed to function in both cooling-only and heat pump applications where a fixed orifice metering device is specified by the manufacturer.

Can I use the 11W10 to replace a TXV?

This is a fixed-bore metering device. It should only be used in systems designed for a piston or as part of a piston-to-TXV conversion if the technical data for the specific evaporator coil supports the change.

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Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.