Your oil furnace is quite reliable, and usually highly effective if it’s less than fifteen-years-old, however, if it does stop heating suddenly, there are some basic steps in oil furnace troubleshooting that you can take before calling the repairman for help. Have your owner’s manual handy for reference to our oil furnace parts and questions about their locations.

The 5 steps of oil furnace troubleshooting

If your oil furnace won’t start

If your oil furnace goes out on you, the first thing you should do is press the reset button for ignition of your furnace fire. The primary control at the stack will support the reset switch on older oil furnaces, and on the newer models, it will be on the burner motor. Never push the reset button more than twice. If the furnace doesn’t turn and stay on within a minute, however, check the fuses or circuit breaker. If you continue pressing the reset button, it will flood the combustion chamber. Should it then have a starter fire, it will then ignite the oil in the combustion chamber.

If the burner motor burns out

Your burner assembly motor usually has a life of 15 years or more, but if it does burn out, you must have a technician replace it. Using too much oil to lubricate the motor is a typical cause if the motor burns out. Should it be a faulty switch on your motor, this would be considered minor (cheap) oil furnace repair job.

If your burner is running, but you see no fire

If you have no fire, but your burner has no fire, the burner nozzle is probably clogged. Since the nozzle opening is tinier than a pinpoint, it is easy to clog with any kind of waste. It should be replaced periodically, anyway to prevent a problem later on.

If no fire, check for water

There may be water in your oil supply line if there is no fire. First, you must disconnect the oil supply line. It runs from the burner assembly. Then, catch the fuel in a clean glass. If there’s water, you will see it when you hold it in front of the light.

If the burner is running, the furnace has fire, yet not enough heat is coming through the registers

If you have insufficient heat, but there is fire, and the burner is running, check the air filter. Change it if it’s filthy. Surprisingly to homeowners of an oil furnace, with these symptoms, that is typically the reason for insufficient heat. There is simply no airflow to help the furnace combust the fuel.

You should change the air filter twice a year, anyway. Make sure your clothes dryer is not near the furnace, as it can cause a lint build-up on your filter. If the air filter is not the problem, check your fan belt. Just open the inspection door to the supply-air fan, to see if the belt is broken.


If your oil furnace does ever go out on you, often you will need a licensed company such as ours. However, if you’re somewhat knowledgeable about the problem with your oil burner, follow the oil furnace troubleshooting steps as described above, and know the repair needed. You then can make a very educated assessment to our technicians about what the problem is.

For more info, Call Us At (810) 653-4328.

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