OEM Lennox Heat Exchanger — 99W42
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The genuine OEM Lennox 99W42 heat exchanger is the core heating component of your Lennox gas furnace, transferring heat from the combustion gases to the circulating air while keeping those flue gases safely separated from your home's air supply. It is manufactured to Lennox's exact metallurgy and tolerances for a correct, safe fit.
A compromised heat exchanger often reveals itself through visible cracks or rust, a flickering or rolling burner flame, soot buildup, unusual odors, or an elevated carbon monoxide reading. Because a breached exchanger can allow combustion byproducts to mix with your indoor air, this is a safety-critical part that should be replaced promptly by a qualified technician.
OEM is essential here: Lennox designs the 99W42 with specific alloys, thickness, and geometry to withstand thermal cycling and maintain a sealed combustion path over the life of the furnace. Generic substitutes risk poor fit, premature cracking, and safety hazards. This authentic Lennox heat exchanger restores efficient, reliable, and safe heating for your equipment.
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