ASI's  Oil Furnace Troubleshooting

Common Oil Furnaces Troubleshooting Tips

• First things first with all Oil Furnaces, have you checked to be sure you have fuel in the fuel oil storage tank. You need to make sure as this is a more common mistake.
• Once you are sure you have fuel in the tank make sure the fuel line is not leaking anywhere, look for stains where the fuel has bee leaking, you should smell it as a strong odor if the leak is fresh. Leaks in the fuel line can cause air to get into the system and the fuel pump can lose prime and stop pumping oil.

• Is the thermostat's system selector switch in the "heat" position?
• Is the thermostat's temperature set point at least three degrees higher than the temperature inside?
• Is your thermostat electronic? Some electronic  thermostats operate from batteries and if they are okay the LCD display should be visible. Many times if the LED display is not visible this may also indicated that the power to the furnace is off (see below). If you think you have a thermostat that runs off of batteries you can usually change the batteries by carefully removing the thermostat from the wall mount as the batteries are generally located inside the thermostat.
• You can test your thermostat if it has switch or button to control the indoor blower or fan, switch it to "on." Listen to hear if the blower or fan comes on. If you do not hear any fan or there is no air coming from your supply registers then check to be sure the power is on at the indoor unit (oil furnace). (see below) If the power is on and you do not hear the fan running this may indicate that you have a bad capacitor, blower motor or other common issue.

• Your heating system may have a power switch at the oil furnace or indoor unit. In most homes in the Treasure Valley area the power switch looks just like a regular light switch and is generally located right on or beside the oil furnace or indoor unit. Make sure the switch is on.
• Most oil furnace heating systems have another hidden switch that shuts off your unit if the front service panel or blower door is removed. Make sure all the service panels are on and secure.If the fan still does not operate check to see if any electrical panel circuit breakers are tripped. Usually if a circuit breaker has tripped it will not be fully in the "on" position. To reset the circuit breaker turn it off all the way and then back on.

• The Oil furnace has what is called the combustion blower and motor, do not confuse this with the blower that moves the air in the house. The combustion blower is usually part of the burner assembly on the front of the unit.
• Immediately upon any call for heat this combustion blower will run, the oil pump is normally also connected to the same motor as the combustion blower motor and the fuel pump will run with the combustion blower so if you have a blower operating you normally have a fuel pump operating also.
• Nearly all oil furnaces have an intermittent spark ignition and no pilot light so do not look for a pilot light. Once the combustion blower has run for a few seconds to clear the combustion chamber you can usually hear the system open the oil supply and try to light the flame with a spark from the spark igniters or probes. (makes several clicking sounds) Normally it will try this for a few seconds and if no flame is present it will shut down at this point and require a reset.
• Once the flame lights the safety system or control board confirms the flame and monitors the flame. The blower that circulates air through the home usually starts and runs based on the temperature in the heat exchanger box, no heat or flame and the blower will not run.