OEM Lennox Oil Burner — 45M40

The genuine OEM Lennox 45M40 oil burner is the heart of your Lennox oil-fired furnace, atomizing and igniting fuel oil to produce the clean, controlled flame that heats your home. Engineered to precise factory specifications, it delivers stable ignition, proper air-to-fuel mixing, and the rated combustion efficiency your Lennox system was designed to achieve.

When an oil burner begins to fail, the warning signs are hard to miss: hard or delayed starts, frequent lockouts on the primary control, sooty or smoky exhaust, a rumbling or pulsating flame, oil odors, and rising fuel bills as combustion efficiency drops. A worn or failing burner can also cause the furnace to short-cycle or fail to reach set temperature on cold days.

Choosing OEM matters with Lennox equipment. The 45M40 is built to the exact dimensions, electrical characteristics, and flame geometry Lennox validated for your furnace, ensuring correct mounting, safe operation, and compatibility with the factory primary control. Generic substitutes can throw off combustion tuning, trigger nuisance lockouts, and void warranty coverage. Install the part Lennox specified and restore clean, efficient, dependable heat.