OEM Lennox Secondary Heat Exchanger — 92L75

The genuine OEM Lennox 92L75 secondary heat exchanger (also identified as part 20292101) is the condensing-stage component in your high-efficiency Lennox furnace. It extracts additional heat from the flue gases after they leave the primary exchanger, condensing water vapor to recover energy that would otherwise be lost — the key to your furnace's high AFUE rating. Built to exact Lennox specifications, the 92L75 restores peak efficiency and reliable, safe operation.

Common failure symptoms: Secondary heat exchangers are prone to corrosion from acidic condensate, showing up as pinhole leaks, cracks, or rust. Symptoms include water leaking near the furnace, reduced efficiency and higher gas bills, a flickering flame, pressure-switch or ignition lockouts, or carbon monoxide detector alarms. A corroded secondary exchanger should be replaced promptly for safety and performance.

Why OEM matters: The condensing environment demands the precise stainless or coated alloy, weld quality, and drainage geometry that only Lennox engineers into the 92L75. Generic substitutes risk rapid corrosion and unsafe operation. Choosing OEM guarantees a factory-correct fit, protects your Lennox warranty, and restores your furnace's designed high-efficiency performance.