A furnace that runs for a minute (or two), stops briefly, and then restarts only to repeat the cycle is said to be short-cycling. A short-cycling furnace wastes energy and doesn't produce the necessary heat to keep the house comfortable. Various things can cause a furnace to short-cycle, but these two are the most common causes:

Restricted Airflow 

Efficient airflow is necessary not only to help the furnace to heat up the house but also to keep the furnace within its operating temperatures. When airflow is restricted, the heat generated by the furnace isn't dispersed through the house (as it should), the furnace overheats, and its inbuilt safety feature shuts its down. The furnace then restarts after it has cooled down. Here are a couple of reasons a furnace's airflow may be restricted:

Dirty Filters

The filters don't just clean the air you breathe; they also clean the air that circulates through the furnace. If the filter gets too dirty, it reduces the volume and speed of air flowing over the heat exchangers. The heat exchangers then overheat and the furnace shuts down to prevent damage or fire outbreak.

Blocked Air Vent Registers

The air vents are responsible for channeling air in and out of your heating system. If the vents are blocked, the air doesn't flow, overheating occurs and the furnace shuts down. Carelessly arranged furniture is one of the most common causes of blocked air vents.

Impaired Heat Exchange

The air flow can be as perfect as it can, but your furnace will still short cycle if the heat exchange isn't taking place. The most common cause of heat exchange failure is dirty heat exchanger coils. Debris accumulation over the coils insulates the coils from the air flowing over them. The heat then remains within the coils and causes them to overheat, and the result is as described above.

Thermostat Malfunction

The thermostat regulates your home temperature by turning on when the temperature falls and turning off when the temperature rises to a preset level. Therefore, a malfunctioning thermostat can turn off the heater before the desired temperature is reached.

Most thermostats today are digital electronic devices, which mean a problem with their internal circuitry can easily lead to a malfunction. Apart from that, the location of a thermostat may also cause it to malfunction. For example, a thermostat located near a window may be affected by direct sunlight or heat from outside, causing it to register a false high temperature and shut down. For more information, contact companies like Edwards Heating & Air Conditioning LLC.