Description
Lennox 12K44 Five-Tube Heat Exchanger
The Lennox 12K44 is a genuine OEM replacement heat exchanger designed to restore efficient and safe heating performance to compatible Lennox furnace systems. Featuring a five-tube configuration, this heat exchanger transfers combustion heat to circulating air while keeping flue gases fully separated from the conditioned airstream — a critical function for both system efficiency and occupant safety.
Key Features
- Genuine Lennox OEM replacement part (SKU: 12K44)
- Five-tube heat exchanger design for effective heat transfer
- Engineered to maintain proper separation of combustion gases from supply air
- Built to Lennox quality and dimensional specifications for a precise fit
- Helps restore original heating efficiency and system reliability
- Designed for direct drop-in replacement in compatible Lennox furnace models
Why Replace Your Heat Exchanger?
A cracked or deteriorated heat exchanger can allow harmful combustion byproducts — including carbon monoxide — to enter the living space. Replacing a failed heat exchanger with a genuine Lennox OEM part ensures the furnace returns to safe, code-compliant operation and maintains the manufacturer’s performance standards.
Application
- Direct OEM replacement for compatible Lennox furnace models
- Suitable for residential forced-air heating systems
- Consult Lennox model compatibility documentation or your distributor to confirm fitment before installation
Installation Notes
Heat exchanger replacement should be performed by a qualified HVAC technician in accordance with local codes and Lennox installation guidelines. Always verify compatibility with the specific furnace model and serial number prior to installation.









