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Lennox

OEM Lennox Stainless Steel Heat Exchanger — 53K78

SKU: LNX-53K78 Brand: Lennox
$399.95 $549.95

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Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The genuine OEM Lennox 53K78 stainless steel heat exchanger assembly is the heart of your Lennox gas furnace's heating cycle, transferring combustion heat into the air circulated through your home while keeping flue gases isolated from your indoor air. Its stainless steel construction stands up to repeated heating and cooling cycles, resisting the cracking and corrosion that lead to premature failure.

Common failure symptoms: Telltale signs of a bad heat exchanger include visible cracks, rust, or soot, burner flames that flutter or roll out, a noticeable odor while the furnace runs, and carbon monoxide detector activation. Homeowners may also see declining heat output, repeated shutdowns on the high-limit switch, and popping or ticking noises at startup as the metal stresses.

Why OEM matters: The heat exchanger is a critical safety barrier, so an exact-fit, properly welded replacement is essential. The genuine Lennox 53K78 is built to factory tolerances and stainless steel specifications, ensuring a sealed, correct fit that aftermarket alternatives can't guarantee. Installing the OEM part protects your family's air quality, restores rated efficiency, and helps maintain warranty coverage.

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 Stainless Steel Heat Exchanger — 53K78?
Yes. This is the factory-specified OEM heat exchanger for the Lennox OEM Lennox Stainless Steel Heat Exchanger — 53K78. 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 Stainless Steel Heat Exchanger — 53K78?
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