Lennox 49K03 Expansion Valve

The Lennox 49K03 Expansion Valve is a critical metering device engineered for precise refrigerant management in 3-ton R22 air conditioning systems. As a direct OEM replacement part, this thermostatic expansion valve (TXV) features a 1/4" flare (FLR) connection, ensuring a secure, leak-resistant interface with the liquid line. Also identified by catalog number 49K0301 and model 041239-07, this component is essential for maintaining the correct evaporator superheat, preventing liquid slugging and protecting the compressor from premature failure. The Lennox 49K03 is constructed with corrosion-resistant internal components to withstand the high-pressure demands of legacy R22 HVAC systems. Whether you are performing a full system overhaul or a targeted repair, utilizing this genuine Lennox expansion valve ensures the system operates within its original factory specifications for optimal heat transfer and sensible cooling capacity.

Key Benefits for Technicians:

• Precision Refrigerant Metering: Maintains consistent superheat levels across varying load conditions to optimize 3-ton system performance.
• Exact OEM Compatibility: Replaces Lennox part numbers 49K03 and 49K0301 without the need for field modifications or piping adjustments.
• Durable Construction: High-grade materials resist internal wear and external corrosion, crucial for long-term HVAC system reliability.
• Simplified Installation: Features standard 1/4" flare fittings for efficient field replacement, reducing labor time on the job site.

Common Questions:

Is the Lennox 49K03 compatible with R410A systems?
No, this valve is specifically calibrated for R22 refrigerant flow characteristics. Using this valve with R410A will lead to improper metering and potential system damage.

What is the difference between 49K03 and 49K0301?
These parts are technically identical. The Lennox 49K03 is the base part number often referenced in service manuals, while 49K0301 is the updated catalog iteration of the same valve.

Can this valve be used on systems smaller than 3 tons?
This TXV is sized for 3-ton cooling capacities. Installing it on a smaller tonnage system may cause the evaporator to flood, as the orifice is bored for a higher refrigerant mass flow rate.

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.