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Lennox

OEM Lennox Secondary Heat Exchanger Assembly — 80M47

SKU: LNX-80M47 Brand: Lennox
$399.95 $549.95

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Texas CMBL #19328542014
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Govt POs Accepted

The genuine OEM Lennox 80M47 is a secondary heat exchanger assembly (also referenced as R20539401) used in high-efficiency condensing gas furnaces. The secondary heat exchanger extracts additional heat from the flue gases after they leave the primary cell, condensing water vapor to boost AFUE efficiency and lower fuel costs. It is a critical safety and performance component that keeps combustion byproducts separated from the conditioned air stream in your home.

Common failure symptoms: Watch for visible cracks or corrosion, water leaks around the furnace base, rust flakes, unusual flame movement when the blower runs, soot buildup, or a furnace that repeatedly trips on a safety limit or pressure switch. A compromised heat exchanger can allow combustion gases to mix with supply air, making prompt replacement essential.

Why OEM matters: Lennox condensing furnaces are engineered to exacting tolerances, and the 80M47 is built from the specified stainless-steel alloys with the correct pass geometry and gasketing to seal properly and resist condensate corrosion. An OEM assembly ensures a precise fit, maintains rated efficiency, and protects both your warranty and your family's safety. Aftermarket substitutes rarely match the metallurgy or dimensions required for reliable long-term operation.

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

Frequently Asked Questions

Does this Heat Exchanger fit my Lennox OEM Lennox Secondary Heat Exchanger Assembly — 80M47?
Yes. This is the factory-specified OEM heat exchanger for the Lennox OEM Lennox Secondary Heat Exchanger Assembly — 80M47. 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 heat exchanger on my Lennox OEM Lennox Secondary Heat Exchanger Assembly — 80M47?
Refer to your equipment service manual for model-specific steps. General approach: turn off power, photograph connections, remove old part, install new part, restore power and test. For gas components, hire a licensed technician. Email info@nationalhvacparts.com for guidance.
What symptoms mean I need a new heat exchanger?
Common symptoms: unusual noises, intermittent operation, complete failure, or visible damage. Visit our diagnostic hub for symptom-based troubleshooting.
Is this heat exchanger 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 heat exchanger?
OEM recommended for reliability and warranty compatibility. OEM parts match exact factory specifications for proper fit, performance, and safety. While aftermarket alternatives cost less upfront, the risk of improper fit and reduced lifespan usually makes OEM the better value long-term.
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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Mike Rivera
HVAC Parts Specialist — Online