Same-day shipping before 3PM CST · 35,000+ OEM Parts · Texas CMBL & SAM.gov Registered · Government POs Accepted

Menu

Home Shop All Account Cart

IMAGE COMING SOON

Lennox

OEM Lennox Heat Exchanger Assembly — 33M65

SKU: LNX-33M65 Brand: Lennox
$399.95 $549.95

OEM Guaranteed

Same-Day Ship

30-Day Returns

Secure Checkout

Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The genuine OEM Lennox 33M65 heat exchanger assembly (also listed as LB-94782W) is the heart of your Lennox gas furnace's heating cycle, transferring burner heat into the supply air while safely venting combustion gases away from your home. Manufactured to factory specifications, it delivers the exact thermal performance and safe separation your furnace was designed around.

Signs that a heat exchanger needs replacement include visible cracks, rust or scaling, a burner flame that flickers or changes shape when the blower runs, soot accumulation, unusual odors, and carbon monoxide detection. Given the safety implications, a damaged exchanger warrants immediate attention from a qualified technician.

Opting for the OEM Lennox 33M65 is important because its alloy composition, wall thickness, and construction are engineered for your furnace's specific firing rate and airflow. Non-OEM parts may not seal correctly or withstand thermal cycling, leading to early failure and lost efficiency. The factory assembly ensures a precise fit, dependable operation, and continued warranty protection for your Lennox system.

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 Heat Exchanger Assembly — 33M65?
Yes. This is the factory-specified OEM heat exchanger for the Lennox OEM Lennox Heat Exchanger Assembly — 33M65. 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 Heat Exchanger Assembly — 33M65?
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.
Home Shop Search Account Cart
Fitment Guaranteed
MR
Mike Rivera
HVAC Parts Specialist — Online