Have you noticed your furnace turning itself on and off every couple of minutes? That’s called “short cycling,” and it’s a serious threat to the health of your system. If not fixed as quickly as possible, it can easily shorten the life of the system and make breakdowns more likely. Let’s take a look at why short cycling happens, and the damage it can cause.
The Cause of Short Cycling
Short cycling is the result of heat becoming trapped in the furnace, typically because of a clogged air filter. This cuts off the flow of cool air from the home into the furnace, which is necessary to maintain a safe temperature. As the temperature inside the furnace rises, the limit switch activates and shuts down the system to protect it. The limit switch cannot treat the root cause of the problem, though. This means that when the furnace turns on again, it will quickly overheat and be shut down again. This cycle continues indefinitely until the air filter is cleaned or replaced.
Damage Caused by Short Cycling
Being locked into the startup cycle (the most stressful part of its operation) is terrible for the furnace. It puts the system under far more strain than it was designed to handle, and prevents it from getting far enough in its cycle to actually heat the home properly. Eventually, the added stress will cause parts of the furnace to begin breaking down. If the short cycling continues unabated, the wear and tear on the system will become so great that the furnace will break down entirely. This is why if you hear your furnace short cycling, you should turn it off and call for repairs as soon as possible.