What are the specs for this Valve?

The correct replacement for Lennox model OEM Lennox Valve-Expansion — 31C79 is this exact part. It is the factory-specified replacement with exact OEM specifications. Using a part with different specifications can cause equipment damage or void your warranty. You can verify this by checking the data plate on your Lennox equipment which lists the model number OEM Lennox Valve-Expansion — 31C79.

What symptoms indicate I need a new valve?

Common symptoms that indicate you need a new valve include unusual noises, intermittent operation, complete failure to operate, or visible damage. For specific diagnostic guidance, visit nationalhvacparts.com/pages/hvac-diagnostic.

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Lennox

OEM Lennox Valve-Expansion — 31C79

Name: OEM Lennox Valve-Expansion — 31C79
Brand: Lennox
SKU: LNX-31C79
Price: 59.95 USD
Availability: InStock

SKU: LNX-31C79 Brand: Lennox

$59.95 $84.95

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The Lennox 31C79 is a genuine OEM expansion valve designed to precisely meter refrigerant flow into the evaporator coil, ensuring optimal heat transfer and system efficiency. If your Lennox system is experiencing poor cooling performance, icing on the evaporator, or erratic superheat readings, a faulty expansion valve is often the cause. This direct OEM replacement is engineered to Lennox specifications for reliable, long-lasting performance in compatible Lennox heating and cooling systems.

Shipping Information

Orders placed before 3PM CST ship same business day
Standard delivery: 2-5 business days
Express shipping available at checkout
Free shipping on orders over $75
Tracking number emailed upon shipment

Return Policy

30-day returns on unused parts in original packaging
Electrical parts (capacitors, contactors, control boards) are final sale once installed
Email info@nationalhvacparts.com to initiate a return
Refunds processed within 5-7 business days

OEM Lennox Valve-Expansion — 31C79

$59.95

Frequently Asked Questions

Does this Valve fit my Lennox OEM Lennox Valve-Expansion — 31C79?

Yes. This is the factory-specified OEM valve for the Lennox OEM Lennox Valve-Expansion — 31C79. It is a direct drop-in replacement that fits without modification. Always verify the model number on your equipment nameplate before ordering.

How do I replace the valve on my Lennox OEM Lennox Valve-Expansion — 31C79?

Requires licensed HVAC technician. Gas valve work involves gas lines that must meet local building codes. Improper installation risks dangerous gas leaks. Buy the part yourself to save 40–60% on markup, then have your technician install it.

What symptoms mean I need a new valve?

Common symptoms: unusual noises, intermittent operation, complete failure, or visible damage. Visit our diagnostic hub for symptom-based troubleshooting.

Is this valve compatible with Bryant or Payne too?

Many Lennox parts are cross-compatible with Bryant and Payne since all three brands are manufactured by Carrier Global Corporation. The same physical part is often used across brand labels with different model numbers. To verify: check your Bryant or Payne equipment service manual for cross-compatible part numbers, or email info@nationalhvacparts.com with your model number.

Should I use OEM or aftermarket for my Lennox valve?

Always use OEM. Gas valves must match exact pressure ratings, port configurations, and safety certifications. Non-OEM gas valves can create safety hazards and may violate building codes.

How fast does National HVAC Parts ship?

Orders placed before 3:00 PM CST ship the same business day. Standard delivery is 2–5 business days anywhere in the continental United States. Express shipping available at checkout. We ship from Houston, TX to all 50 states. 30-day return policy on all parts.

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OEM Lennox Valve-Expansion — 31C79

Shipping Information

Return Policy

Frequently Asked Questions