Worn or Dirty Nozzle

• Oil furnaces periodically need maintenance and cleaning to assure they operate at peak efficiency. The nozzle that sprays the fuel in the refractory pot can sometimes become dirty; this reduces its ability to atomize the fuel. This causes incomplete combustion that leads to excessive soot. The nozzle also becomes worn with years of use. Small particles in the fuel slowly wear away the leading edges reducing its effectiveness.
  
  

Clogged Oil Filter

• The filter of an oil furnace cleans the fuel before it reaches the burner. If the oil filter is not changed regularly it can become clogged with dirt. This reduces the amount of fuel that reaches the burner, throwing the air-to-fuel ratio off. When the burner receives more air than fuel, it can create excessive soot because it is not burning properly.
  
  

Poor Burner Adjustment

• When a oil furnace is installed, the technician must adjust the burner's air-to-fuel ratio. This is typically done by adjusting a gate that allows more or less air into the burner. If set incorrectly, the burner runs inefficiently and additional soot can accumulate.
  
  

Poor Oil Quality

• Once or twice a year your local oil company fills your heating oil tank. The quality of this oil can affect the efficiency of the burn in the refractory pot. The oil may even be contaminated with water or other foreign materials that can affect the quality of the burn.
  
  

Worn Fuel Pump

• As a fuel pump ages, its impellers wear out. This reduces the amount of fuel that is delivered to the burner, thus throwing the air-to-fuel mix off.
  
  

Maintenance

• Have your oil furnace inspected and cleaned once a year. This is ideally done in the late summer or early fall, just prior to the heating season. A skilled technician can adjust your burners for peak efficiency and clean the unit. Yearly maintenance is key to a long lasting, trouble-free oil furnace.