How to Maintain My Oil-Fired Boiler

Updated March 23, 2017

Oil-fired heating systems use a boiler that burns oil from an external tank or oil line to circulate hot water through pipes that are connected to radiators or underfloor radiant heating systems. They also produce burner byproducts that you must pipe outside the building through a chimney or flue. The boiler is the central component of an oil-fired heating system. Performing regular maintenance on it can avoid the need to call in an expensive contractor to repair them after a breakdown.

Watch the colour of the smoke coming out of your chimney or flue. Seeing black smoke is a clear sign that you have a problem with oil combustion.

Shut off oil lines and turn off the boiler before doing any maintenance.

Change the oil filter regularly. Impurities such as dirt and water can keep the fuel from burning properly. The oil filter catches these impurities. If it starts to clog, the boiler's efficiency will decline. Check your boiler's manual for exact instructions on how to change the filter.

Lubricate the burner motor and clean out dust and grime on a regular basis. Dirt build-up wears down the motor and shortens its life. Pick up loose dust with a vacuum. Wipe grease and dirty oil away with a rag. Degrease the motor with a lubricant recommended in the owner's manual for the boiler.

Check for leaks around the burner mounting plate. Black streaks are a sign that smoke from the burner is escaping into the room and air is disrupting the proper combustion mixture in the burner. Tighten the plate yourself if possible; otherwise, call a contractor to make repairs.

Inspect the boiler's electrical system regularly for any tripped breakers or reset buttons, which would indicate an electrical problem. Replace frayed or worn wiring after shutting off the power to the circuit.

Replace any damaged or corroded pipes in the exhaust stack. Seal any bad pipe connections with tape rated for exhaust ducts.

Clean out the draft regulator thoroughly and often. This hinged plate controls the rate at which exhaust is drawn into the chimney or flue. Collect dust with a vacuum, then wipe the whole draft regulator clean of grease and oil with a rag.

Sweep and vacuum the room around the boiler. Otherwise, dust and dirt from the room will get sucked into the boiler, gradually fouling the burner. Keep the room as clean as possible to reduce the need for more intensive cleaning.


For tasks beyond basic maintenance, hire a tradesman. Heating systems are complex and a bad repair could admit noxious gases into your home.

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About the Author

Joshua Smyth started writing in 2003 and is based in St. John's, Newfoundland. He has written for the award-winning "Cord Weekly" and for "Blueprint Magazine" in Waterloo, Ontario, where he spent a year as editor-in-chief. He holds a Bachelor of Arts in political science and economics from Wilfrid Laurier University.