Oil burners, although certainly an older device for heating purposes, are still in use today in many older homes and businesses. Oil burners consist of oil fuel tanks and a supply line that leads to a pump. The pump sends high pressure fuel to a nozzle, which atomizes the fuel into a fine mist. The oil-fuel mist is ignited by an ignition transformer, which creates the heat in the furnace. Sometimes heavy accumulations of sludge build up in the filter and screens, but it can also clog and block off the fuel lines or pipes from the tank to the pump and pump to the nozzle. Clearing the lines involves a few processes to restore proper flow and pressure.
Things You'll Need
- End wrenches
- Oil burner service manual
- Solvent cleaner (pressurized)
- Plastic bucket
- Oil pressure gauge (0 to 300 PSI)
- CO2 can (pressurized)
- Plastic tube (3/8 inch)
Locate your oil burner unit, usually in the basement of your house or a separate housing shed outside. Find your reset button and push it, but only once if you haven't done so. If the unit fails to come on, check your fuel level; it is possible you have run the fuel tank dry.
Find the oil burner nozzle at the intake portion of the furnace, if your oil burner unit operates. Use one end wrench on each separate flange nut -- one is attached to the copper fuel line and the other nut is part of the nozzle. Turn the nozzle counterclockwise while holding the line nut steady. Remove the nozzle and check the porous filter on the end of the nozzle. Spray the filter with pressurized solvent cleaner and wipe it dry with a rag.
Attach an oil pressure gauge fitting to the end of the copper line that exits the pump. Use gauge adapters to make the connection; it's usually a 3/8-inch fitting. Wrap rags around the attachment fitting to guard against any high-pressure spray and set a plastic bucket underneath it. Hold the gauge while you have an assistant turn on the burner switch.
Read the pounds per square inch on the oil pressure gauge. Refer to your oil burner service manual for the proper pressure required of your system. Generally, if the reading is significantly below 100 PSI, then you have a line clog or flow problem. Turn off the oil burner. Use an end wrench to loosen the flare nut on the fuel line that routes from the pump to the furnace.
Place a plastic tube on the end of a pressurized CO2 can and connect the other end of the tube to either end of the fuel line. Have your assistant hold the open end of the line inside the bucket opposite you, while you open the valve on the CO2 can. Blast the line clean.
Use an end wrench to disconnect the fuel line from the tank to the pump. Have your assistant support one end of the line inside the bucket. Connect the CO2 can tube to the other end of the line and turn the valve on. Blast the line clear. Reconnect the tank to the pump fuel line with an end wrench. Use an end wrench to reconnect the fuel line that exits the pump. You should have only one line opening now, which is the nozzle end.
Hold the fuel line inside the bucket while you have your assistant turn on the oil burner. Allow all the air to escape the line until you see solid fuel flowing, and then shut off the oil burner. This purges the lines of air. Reconnect the nozzle to the furnace and the fuel line to the nozzle with the two wrenches. Wipe up any fuel spills on the floor or on the component. Turn on the oil furnace and watch for proper ignition and operation.
Tips & Warnings
- Be careful when igniting an oil burner after you have serviced the nozzle and fuel lines. Wipe up all spilled fuel in the area, including your clothing, shoes and hands.
- Do not depress your reset button more than once. Some units have a fail safe device that will lock you out, disallowing activation of the unit. This safety feature protects you and the equipment. Shut off the main power switch to the burner and call a certified technician for this problem.
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