What is a likely symptom indicating the need to check for a down draft issue in a furnace?

A common symptom indicating a down draft issue in a furnace is that the pilot light frequently goes out. This can occur when the ventilation system is compromised, preventing the proper flow of exhaust gases from the combustion chamber. A down draft can cause these gases to flow back into the furnace rather than leaving through the flue. As a result, the pilot light may not remain lit due to insufficient oxygen or the buildup of harmful gases. Addressing this issue is essential to ensure safe and effective operation of the furnace.

The other options do not indicate a down draft issue. A steady pilot light typically signifies that the combustion process is stable. If a furnace runs too efficiently, this might indicate it is functioning optimally rather than experiencing a down draft problem. Excessive heat emitted by the furnace could point to other issues, such as thermostat problems or airflow restrictions, but does not specifically indicate a down draft situation.