Learning how to troubleshoot your oil-burning furnace can help you avoid paying for repairs that you can do yourself. A typical repair call may cost several hundred dollars, even when only a small replacement part is needed.
Check the thermostat to be sure it is set correctly before you waste time troubleshooting the furnace unit itself. Make sure the desired room temperature is set higher than the current temperature so the unit will turn on. The thermostat's mode should be set to "heat" and the fan to "automatic." If the heater still does not function properly after correcting the thermostat settings, switch the fan to "on" and move on to check the furnace.
If the furnace's blower fan does not turn on, see if the breaker switch has been tripped or the fuse has burned out. Before resetting the breaker, inspect the furnace wiring for damage. If the breaker was not the issue, there may be a problem in the primary control, fan timer control, run capacitor or the blower motor itself. At this point, you will probably have to call a professional to test these parts. The blower fan is also involved in cooling the unit at the end of a heating cycle. If it does not continue to run for several minutes after the burner has shut off, there may be a problem with the fan timer control or limit control.
If the burner does not turn on, look for the red reset button on the furnace's primary control. If this button is in the upright position, push it back down and test the furnace again. Check the fuel tank and filter if the reset button keeps tripping and shutting off the burner. This may be a sign that there is a clog in the system or it is out of fuel.
If this still does not correct the problem, touch the side of the furnace cabinet to see if it is warm. A cool furnace is an indication of a problem with the primary control, burner motor or flame sensor. If the furnace is warm, the air filter may need replacing, or there is a defect in the limit control. When the burner does start, there should be a distinct sparking sound. If you do not hear this, the primary control or ignition transformer may be defective and should be replaced by a professional.
How to Troubleshoot a Lennox Oil Burner Furnace
The Lennox oil-burning furnace is an environmentally friendly home heating option with efficiency ratings of over 80 percent. The furnace uses oil...