When a furnace is operating efficiently, it cycles automatically once it senses that the rooms are getting cold. It ensures that the office or home is warm enough (per your thermostat settings) before the system shuts itself off. This procedure happens automatically, so most people don't give it much thought.

But, if the furnace starts to turn off and on randomly all day and the rooms aren't warm enough, you'll need to prioritize heating repair. Here are some of the reasons why you may have this problem.

Overheating

When a furnace overheats, it might be trying to protect itself from damage by going off prematurely. However, overheating can damage other components. For instance, it can cause the formation of cracks in the heat exchanger, which will be harmful to your health. This often happens when carbon monoxide leaks into the house. 

So, if you think that this is the reason your heating unit is short cycling, call an HVAC contractor to perform a diagnosis. In most cases, overheating issues occur when the air filters or vents are clogged or due to blockages on the roof exhaust.

Defective Thermostat

A thermostat's function is to control the whole heating system. If the furnace is turning off and on continuously or quickly, it could mean that the thermostat is broken or malfunctioning. Several things can cause a thermostat not to function as expected. For instance, the wiring could be worn out, batteries may be too old, or the thermostat location might not be suitable. 

If the wiring is damaged, the technician will replace it. Old batteries will also be replaced. If the thermostat location isn't ideal, maybe because it is close to a source of heat like sunlight or an appliance, the technician will move it to an appropriate place.

Dirty or Deteriorating Flame Sensors

As the furnace heats your house by burning fuel, it may produce some precipitation. Over time, this moisture can cause corrosion on the flame sensor. This is a safety device in your furnace designed to cut off the power or gas supply when a flame isn't detected. 

When rust or dirt starts to build up, the heating system will begin to short cycle, an issue that is detrimental to your residence's safety. The best way to avert this problem is to inspect and clean the flame sensor. Because this involves working with electricity or gas, you should allow an HVAC contractor to inspect and repair the flame sensor.