What Does the Red Light on My Oil Furnace Mean?

If your oil furnace isn’t coming on, you may see a red light illuminated on the burner unit. When lit, this red light, also called a lockout light, indicates that a safety mechanism on your furnace has caused a shutdown because it has detected a problem or recognized a fault. (Note: Not all furnaces have this red light. Some have a red reset button that does not light up.)

The most common trigger for a shutdown is the absence of a flame when the burner kicks on, but there are many other causes, or it may just be a fluke. If your furnace has a digital display that provides a fault code, you can easily check the fault code to diagnose the problem. If you don’t have a digital display, here are a few things you’ll want to check out first before you press the reset button or call for service.

Make sure you have oil in your tank. If no oil is reaching the furnace, it won’t fire, which will trigger a shutdown. Check the oil gauge to make sure you have oil, and if you’re out of oil, call for delivery. To prevent this from happening again, consider signing up for automated delivery. That way you won’t have to worry about forgetting to fill your tank.

Make sure the oil valve is open. A closed oil valve prevents oil from getting to the burner and will prevent the burner from firing. When no flame is detected, the furnace will shut down. Open the valve if you see that it’s closed.

After checking your oil supply and oil valve, press the reset button. Typically, the reset button and the red light are the same button, but sometimes they’re not. If they’re not, the reset button is usually located nearby. Press and release the reset button to see if the furnace will fire. If it does, and this happens only once, it was probably a fluke. But if your oil furnace keeps shutting down, DO NOT REPEATEDLY PRESS the reset button. Call a professional, as this is a sign of a more serious problem.

Automatic shutdown of your furnace is a safety feature designed to protect you and to keep your furnace from experiencing additional damage beyond whatever condition caused it to shutdown in the first place. Many of the causes of a shutdown, such as a blocked filter or a failed fuel pump, can be avoided if you have your oil furnace serviced annually. Your service technician will make sure all of the components are clean and functioning properly, which will give you peace of mind throughout the heating season.

To learn more or schedule service, call HB McClure at 717-232-HEAT (4328) or schedule an appointment online.