What Is Short-Cycling, and Why Should I Worry About It?

Have you ever noticed your furnace behaving strangely? Shutting itself on and off every couple of minutes, for example? If you have, you’ve got a pretty serious problem. That behavior is one of the most damaging things that can happen to heating systems, known as “short-cycling.” So what is short-cycling, really? What does it do, and why should you care? Read on to find out.

Causes of Short-Cycling

There is one major cause of short cycling when it comes to furnaces: clogged air filters. The air filter is a fiber mesh that is inserted into the air return duct of the furnace. It is designed to protect the furnace against any particles that may blow in from the ducts, such as dust and dirt. The air filter captures these particles, while allowing the air to flow through it and into the furnace. While this works fairly well under normal circumstances, the air filter has no way to actually get rid of the particles that it captures. That means that sooner or later it will need to be cleaned or replaced. If this is not done, the air filter will become so clogged with particles that it will restrict the air flow into the furnace.

When the air flow into the furnace is obstructed, its internal temperature will begin to rise. Eventually, it will rise high enough to activate the limit switch, which is designed to shut down the furnace if it is in danger of overheating. This is only a temporary fix, however, as the air filter is still restricting the air flow into the furnace. Once the furnace starts back up, it will overheat again and be shut down again. This process will continue as long as the air filter remains clogged.

The Results of Short-Cycling

If not fixed immediately, short-cycling will start to inflict severe damage on the furnace. The startup sequence of the heating cycle is the most stressful, and also happens to be the part that the furnace becomes trapped repeating. This constant repetition of the most stressful part of the heating process puts the system under much more strain than it was designed to handle. A furnace often has its lifecycle severely shortened if left to short-cycle for a long period of time, and will have an increased chance of breaking down.

If you suspect that your furnace may be short-cycling, call Comfort Flow Heating for our comprehensive heating services in the Florence, OR area.