OEM Lennox Heat Exchanger — 33M15
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The genuine OEM Lennox 33M15 heat exchanger is the heart of your Lennox gas furnace, transferring heat from the combustion process to the air circulating through your home while keeping toxic flue gases fully separated from the airstream. Precision-formed to Lennox specifications, this direct factory replacement restores safe, efficient heating performance to your system.
Common failure symptoms: A compromised 33M15 heat exchanger may show visible cracks, rust, or corrosion, produce flame rollout or flickering burner flames, or trigger repeated limit-switch lockouts. Cracks can allow carbon monoxide to leak into the supply air, so a failed heat exchanger is a serious safety concern that warrants immediate replacement.
Why OEM matters: Heat exchangers are engineered to the exact metallurgy, dimensions, and temperature tolerances of your specific Lennox furnace. Aftermarket substitutes may not seal correctly, dissipate heat properly, or withstand thermal cycling, risking both efficiency and safety. Installing the genuine Lennox 33M15 guarantees a precise fit, correct heat transfer, and the safety integrity your Lennox equipment demands.
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