What should be checked if a furnace’s limit switch trips frequently?

When a furnace’s limit switch trips frequently, it is a sign that the system is overheating or that there are airflow restrictions present. The limit switch is a safety device designed to prevent the furnace from overheating; if the temperature exceeds a certain threshold, the switch activates to shut down the furnace.

If the limit switch is tripping frequently, checking for airflow restrictions is critical. This can include inspecting air filters, ductwork, or registers for blockages that could hinder the proper flow of air. Adequate airflow is essential for the efficient operation of the furnace, as it prevents overheating by ensuring that the heat generated by the burners is effectively distributed throughout the home.

Additionally, it is worth noting that if the furnace is indeed overheating due to insufficient airflow, it could potentially lead to more severe issues, such as heat exchanger damage or increased energy costs due to inefficiency. Therefore, addressing any airflow restrictions or overheating problems should be the priority to restore the function of the furnace and ensure safe operation.