Oil Furnace Do's and Don't

The best maintenance to your oil furnace to help eliminate many problems before they begin.  Using these oil furnace maintenance tips will be a great start.

At the beginning of the heating season:

• Check to see if the smoke is coming from the chimney as expected. If the smoke is black, the furnace is not burning the oil in it's entirely so this would indicate that fuel is being wasted.  This would require adjustments to the Air/Fuel ratio.
• If the blower motor has grease or oil fittings, lubricate with grease or 10-weight non-detergent motor oil available at hardware stores. Don't use all-purpose oil!
• Clean out the blower every few months of use.
• Clean soot from the stack control every few months of use.
• Clean the thermostat before each heating season.

If your furnace isn't working, use the below troubleshooting chart to find a possible solution.

Don't

• Flame Safely Control: If the Safely control has tripped, don't reset it more twice. Every time it is reset, the pump sprays fuel into the combustion chamber if the fuel is not igniting it will build upon the bottom of the combustion chamber. Once your furnace does ignite, that buildup fuel can result in an explosion inside the furnace. This can damage the combustion chamber, vent connector, chimney, and make a complete mess of the house.
• Let the oil tank run dry, when this happens the oil pump will suck in air, this air would have to be purged.

Do

• Change the air filters regularly.
• Change the oil filter regularly
• Check the fan belt for proper tension and wear. Replace if necessary
• Properly service the equipment before the heating season

What is the proper service?

Smoke Test: To set up the Air/Fuel ratio a sample of the exhaust must be tested. By drawing air through a filter paper, the color of which allow the technician to set the air shutter. Too little air will cause shooting, reduce efficiency and restrict the heat exchanger. Too much air will reduce the combustion temperature and reduce efficiency.

Clean the Combustion Chamber: There are normally two inspection ports on the furnace. This allows accessing the secondary flue passage of the heat exchanger, for inspection and cleaning. This can be cleaned using a vacuum (with a good filter ) and a soft brass brush.

Barometric Draft: The swing damper on the vent connector controls the draft up the chimney. If the draft is too high, the hot flue gases will pass through the heat exchanger too quickly, sending the heat up the chimney. A draft should be a set a 0.02"W.C.- 0.03" W.C. This is a very small amount of pressure. If the barometric damper door is sticky at all, it will not control the draft properly.

Oil Pump Pressure: The oil nozzle is designed to work at 100 psi, to provide a proper spray pattern and flow rate of fuel. Higher pressures can cause the furnace to overheat, lower pressure can collapse the spray pattern, resulting in a poor flame. An accurate pressure gauge should be installed on the oil pump.

Oil Nozzle: The oil nozzle meters the flow of oil to the combustion chamber and creates the proper spray pattern which controls the shape of the flame in the combustion chamber. The nozzle consist of a small opening in the tip, a spinner located behind the opening, and a brass filter. The opening can clog up very easily, the spinner will wear at the opening causing the flame pattern to change, and the brass filters can plug up. The nozzle should be changed regularly. Approxmently every 500 hours of operations. A faulty nozzle is often the problem when the furnace fails to light.

Ignitor Position: The Ignitors must be in the proper position to light. The points should be 1/2" above, 1/8" ahead of the nozzle with a 1/8" gap. This works with most oil furnaces. Ignitor Drawing.