What is one possible cause of a gas furnace excessively cycling on and off?

Excessive cycling on and off of a gas furnace can result from a variety of factors, each affecting the heating system's efficiency and performance.

Improper thermostat placement can significantly influence how a furnace operates. When a thermostat is located near drafts, heat sources, or outside walls, it may misread the actual temperature of the living space. This can cause the furnace to turn on and off too frequently, as it reacts to inaccurate readings rather than maintaining a consistent temperature.

Under-sized ductwork is another factor contributing to this issue. If the ductwork is inadequate for the heat output of the furnace, it may not distribute warm air effectively throughout the home. As a result, the furnace might sense that the home is cooler than it should be and cycle on more frequently, leading to inefficient operation and uncomfortable temperature fluctuations.

Dirty air filters can also impede airflow, which is essential for the furnace's functioning. When filters are clogged, the furnace has to work harder to pull air through, often leading to overheating and triggering safety mechanisms that shut off the furnace temporarily. This causes the system to cycle on and off excessively as it attempts to reach the desired temperature.

Since all of these factors can independently disrupt the operation of a gas furnace, the correct answer reflects