Furnace short cycling is when the system is turning on and off more frequently than usual without reaching the set temperature on the thermostat. You will start to notice that your home is not as warm as it should be, leaving you cold and uncomfortable. On the other hand, a properly working furnace will turn on when the temperature in your home drops below the set temperature on the thermostat and warm your home until it reaches the set temperature. Short cycling is an issue that should not be ignored as it leads to energy waste and unnecessary furnace wear and tear leading to major issues and costly furnace repairs or furnace replacement. In this article we will discuss the heating system issues that cause furnace short cycling and solutions.
Dirty Air Filter
A dirty air filter is one of the most common causes of furnace short cycling. A clogged air filter will block airflow, and the blower fan will not be able to move enough air over the heat exchanger. This will cause the heat exchanger to overheat and trip the fan limit switch which will shut down the system. When the system cools down, it will restart the system and the cycle will continue. To best avoid this, replace your air filters before they become clogged at least once every three months and schedule furnace maintenance.
Improperly Sized Furnace
An improperly sized furnace will short cycle. When a furnace is oversized for the home, it will rapidly heat the home, so the cycles are shorter. Although it sounds like it could be a good thing, a furnace with shorter cycles will stress the furnace components faster and lead to furnace breakdowns, shorter lifespan, while also wasting energy, and higher energy bills. A furnace that is too small for your home will struggle to meet the set temperature and will shut off due to reaching its capacity. If either one is the case, the only way to solve the issue is to work with a professional for furnace replacement with a properly sized system.
Flame Sensor Issues
The flame sensor ensures your furnace ignites and stays on. It senses the flames at the burner and allows natural gas to flow. If the sensor is dirty, it will shut off the gas valve and the furnace to prevent natural gas accumulations that could cause a fire resulting in short cycling. Routine cleaning and furnace maintenance can help resolve this issue.
Thermostat Issues
The thermostat controls your furnace so if it is improperly set or malfunctioning it can lead to your furnace short cycling. The first thing to check is that it has been switched over to heating mode and ensure the temperature has been set correctly. Next check and replace the batteries. Another item to consider is the location of your thermostat. If it is near a window, heat source, or in direct sunlight it may register inaccurate temperatures. Consider relocating your thermostat to a more central and insulated area for more accurate temperature readings. Also consider, upgrading your thermostat to a smart or programmable thermostat to increase control and efficiency.
Clogged Flue
If the flue is blocked or damaged it means the gases are not escaping properly and the flue limit switch could cause the system to shut off before the flue gets too hot and to protect you from carbon monoxide poisoning. The flue can become damaged or clogged from rodents or pests making their way in. Get it checked by scheduling furnace maintenance to get it cleared out and your furnace should start working properly.
Damaged Ignition System
If the hot surface ignitor is not working properly the furnace flame sensor will shut down to prevent gas accumulations. Schedule furnace repair if you suspect this issue, it could be a dirty flame sensor or damaged ignitor.
Air Leaks
Sometimes furnace short cycling could be due to poor insulation or air leaks that allow the heated air to escape your home rapidly. This prevents your furnace from heating up your home properly and causes it to short cycle. Check your windows to see if any of them are open or not sealed properly. To help fix this, caulk around the window frames to keep the warm air indoors.
Contact LA Construction, Heating and Air
Furnace short cycling can be frustrating and inconvenient, but there are safety features in place to prevent harm to your family and your home. Routine furnace maintenance can help prevent overheating and can ensure your heating system operates efficiently and properly. If you are experiencing short cycling do not ignore and call for furnace repair today. We can quickly repair most issues with most parts in stock. We care about your comfort, give us a call today or contact us online to schedule service.
