Now that you have been running your furnace daily, you may begin to notice some odd behavior from your home’s heating system. One odd behavior that demands investigating is frequent heating cycles. When a furnace starts up to only shut off abruptly, it is never a good sign. Ambient Heating & Air Conditioning will share some of the causes for frequent heating cycles and what you can due to correct this potential major issue.
When a furnace has frequent heating cycles where they seem to start and run and then quickly shut off to only start back up again, can be caused by a number of different issues. One common cause for frequent heating cycles is restricting airflow. When air flow becomes restricted, the furnace can quickly overheat which causes the furnace to shut down before the heating cycle has finished reaching the desired temperature. Unfortunately, there can be a number of sources for restricted air flow, one being dirty air filters. If the furnace is having frequent heating cycles, check the air filters first. Another common culprit is the air vents. Check all of the air vents in the home and see if they are full or even partially closed. If so, open the air vents all the way, and all throughout the entire home. Another cause for restricted air flow is a dirty blower wheel. If the wheel blades are dirty it will not work properly and not circulate the air causing weak air flow that puts stress on the furnace.
Corroded or Dirty Furnace Flame Sensor
Sometimes frequent heating cycles can be due to a corroded or very dirty flame sensor. A flame sensor is essential as it lets the heating system know when a flame is present when the gas valves are open. If the flame isn’t occurring the gas will shut off to prevent gas from leaking throughout the home. If the sensor is dirty and or corroded, the flame will not register that it is on and the gas will shut off even if the flame is there. This will cause the heating system to shut down, resulting in frequent heating cycles. A professional HVAC technician should either clean or replace the flame sensor if it is the culprit.
Faulty Furnace Flue Pipe
Not a super common problem but one that can occur and cause frequent heating cycles is a faulty flue pipe. When a flue pipe becomes dirty with leaves, debris or birds’ nests, it causes a blockage. If the flue pipe is blocked the furnace can begin to overheat. To prevent major damages to the furnace an internal mechanism will turn off the furnace.
Another cause for frequent heating cycles is when an over-sized furnace was installed. An over-sized furnace can heat up the home rapidly which then forces the furnace to shut off too soon. It may not seem like a major problem. However, enough frequent heating cycles can have other effects in the home and to the furnace which eventually will then require premature replacement.