How Do Oil Burners Work?

Date: June 20, 2019

Oil burner

Like any mechanical device, oilheating systems require all components to work together. But some parts are more important than others. One component that is particularly vital to the efficient and effective operation of a heating oil system is its burner.

The burner can be considered the engine of the heating system. When your house gets chilly, the thermostat will send a signal to tell the oil burner in the furnace or boiler to turn on. A fuel pump then starts to draw the oil from the tank and through fuel lines to reach the oil burner.

There is a piece on the burner called the nozzle, which turns the oil into a very fine spray. This oil mist mixes with air and ignites in the combustion chamber, which gets very hot. This heat then gets moved around your home and comes out either through radiators, baseboards or vents.

How efficiently this is done depends on the design of the burner. Modern burners contain electronic pre-purge and post-purge controls to ensure ultra-clean starts and stops. New two-stage burners also have an efficiency level that’s 5–15% higher than older ones because they have been designed to conserve fuel.

Diagnosing combustion problems

If a burner seems to have combustion issues, it doesn’t always mean the burner is malfunctioning on its own. Sometimes, poor air flow around the system can be the culprit. Poor air flow can be caused by a variety of factors:

  • the furnace or boiler room is always sealed off or closed.
  • insulation or other energy conservation steps have been taken which have made for a very tight house.
  • a clothes dryer, workshop or pet’s living quarters are near the system. Lint, sawdust or animal hair can be drawn into the air openings of the burner and clog it.

If the burner flame looks weak and is orange in color, and if there are signs of soot, there may be a lack of combustion air. To confirm this, open a door or window to bring air to the area around the heating system and watch the burner flame. If it turns a bright white, lack of combustion air is the problem.

If you are uncertain about the cause, the best thing to do is to reach out to your oilheat contractor and arrange for service.