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Is Your Furnace Short-Cycling? Here’s What You Should Know

well. You may lower the temperature on the thermostat, only for your furnace to run for just a few minutes before turning off. While short-cycling may seem harmless, though, it can lead to several problems if not addressed.

What Is Furnace Short-Cycling?

In regards to furnaces, short-cycling refers to an abnormally short heating cycle. Furnaces don’t work instantaneously. When your furnace turns on, it must use either heating elements or burners to warm the air. Electric furnaces use heating elements, whereas gas furnaces use burners. The heating cycle begins with your furnace initially turns on, and the heating cycle ends when your furnace turns off.

Furnaces typically have a 10- to 15-minute heating cycle. After turning on, your furnace should achieve the temperature set on the thermostat and stop running within 15 minutes. Short-cycling involves a shorter run period. Your furnace may only run for five minutes, or it may run for less than one minute.

Failure to fix a short-cycling furnace can result in the following problems:

·         Increased wear and tear

·         Uneven heat (some rooms are warmer than others)

·         Higher heating costs during the winter

Common Causes of Furnace Short-Cycling

Furnaces can short-cycle for any number of reasons. One of the most common causes is an oversized furnace. Both AC systems and furnaces can short-cycle if they are too big for the home in which they are installed. An oversized furnace will quickly warm your home. It will produce a substantial amount of heat in a short period of time, resulting in short-cycling.

A faulty flame sensor can cause your furnace to short-cycle. The flame sensor is a rod-shaped safety device that’s designed to detect the presence of a flame in the combustion chamber. If there’s a flame present, it will allow gas to continue flowing into the combustion chamber. If there’s no flame present, the flame sensor will prevent gas from entering the combustion chamber. With a faulty flame sensor, your furnace may run for a short period, or it may fail to turn on at all.

A clogged flue pipe can cause short-cycling as well. The flue pipe is an exhaust passage for gas furnaces. Electric furnaces don’t have them. Because gas furnaces produce combustion gases, though, they require a flue pipe. If it’s clogged, a device known as a limiter may shut off your furnace while causing it short-cycle.