OEM Lennox Burner Box — 81K79
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The Lennox 81K79 burner box (factory part number LB-84511) is a genuine OEM combustion enclosure for compatible Lennox furnaces. The burner box houses and positions the burner assembly, maintains proper alignment to the heat exchanger, and helps direct combustion air and flame for safe, efficient, and complete fuel burn. Its precise construction is essential to correct flame containment and airflow through the combustion chamber.
Common failure symptoms: A corroded, cracked, or warped burner box can lead to noisy or unstable combustion, flame rollout, delayed ignition, sooting, poor heat transfer, and nuisance safety lockouts. Rust and heat fatigue over years of cycling are the most common reasons the box needs replacement.
Why OEM matters: Combustion components must fit and align exactly to keep the flame properly contained and the heat exchanger protected. The OEM Lennox 81K79 is built to the original dimensions and material specifications of your furnace — generic substitutes can misalign the burners, disrupt airflow, and create safety and efficiency problems. Choose the genuine part for a correct, lasting repair. In stock and ready to ship same day.
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