OEM Lennox 2-Stage Gas Valve 103181-04 — 10A33

The genuine OEM Lennox 10A33 (factory part number 103181-04) is a two-stage gas valve designed for Lennox furnaces that modulate between high-fire and low-fire operation. This valve manages gas flow across two distinct stages, allowing your furnace to run at reduced capacity for efficient, even heating and step up to full output when demand rises. Two-stage control improves comfort, reduces temperature swings, and lowers energy consumption.

Common failure symptoms: When the 10A33 fails, you may notice the furnace stuck on a single stage, no ignition, short cycling, delayed or rough ignition, or a system that trips into safety lockout. Erratic flame behavior or a furnace that no longer modulates between heat levels are also telltale signs of a worn or defective valve.

Why OEM matters: Two-stage valves require exact pressure calibration and staging logic to work with your Lennox control board. The OEM 10A33 is factory-matched to those specifications, guaranteeing correct gas delivery on both stages, proper safety operation, and preservation of your equipment warranty. Aftermarket substitutes rarely replicate the precise two-stage performance your Lennox furnace was built to provide.