The reset button is located on different parts of the furnace depending on the model and manufacturer, but it is frequently found on the burner motor or control module. The reset button loads more fuel into the burner, which can restart a furnace that has gone out.
The reset button on an oil furnace is usually red and easy to spot. If the furnace goes out, hit the reset button once. If the burner is activated, the furnace should work properly. If, however, the burner dies again or the reset button pops back, the user should contact a professional furnace technician for service. Additionally, the reset button should never be pushed more than two times.