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OEM Lennox Bottom Burner Box — 61M21
Lennox

OEM Lennox Bottom Burner Box — 61M21

SKU: LNX-61M21 Brand: Lennox
$49.95 $69.95

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Texas CMBL #19328542014
SAM.gov Registered
Govt POs Accepted

The Lennox 61M21 (factory reference LB-100712D) is the bottom burner box that mounts and aligns the gas burners within your Lennox furnace. It establishes the correct combustion geometry and airflow so the burners ignite cleanly and channel heat into the heat exchanger safely and efficiently. This part is a direct OEM replacement for the original bottom burner box.

A corroded, warped, or damaged burner box can cause flame misalignment, incomplete combustion, sooting, delayed ignition, or nuisance trips on the flame sensor and rollout switch. Symptoms such as yellow or lifting flames, unusual burner noise, or repeated safety lockouts warrant inspection of the burner box and its mounting.

Why OEM matters: Lennox builds the 61M21 to exact combustion tolerances for their furnace models. Aftermarket substitutes can disrupt flame travel, airflow, and burner spacing, undermining efficiency and safety. The genuine OEM box guarantees proper fit, rated performance, and adherence to Lennox specifications.

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 Burner fit my Lennox OEM Lennox Bottom Burner Box — 61M21?
Yes. This is the factory-specified OEM burner for the Lennox OEM Lennox Bottom Burner Box — 61M21. 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 burner on my Lennox OEM Lennox Bottom Burner Box — 61M21?
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 burner?
Common symptoms: unusual noises, intermittent operation, complete failure, or visible damage. Visit our diagnostic hub for symptom-based troubleshooting.
Is this burner 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 burner?
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