An overheating furnace can be problematic, especially during the winter months. When a furnace overheats, the whole system could just shut down abruptly at any unanticipated moment. Worst of all, you may have a difficult time getting the furnace started again, leaving you hopelessly stranded in the freezing cold.
There are several pre-emptive warning signs of a furnace overheating. The most common signs include a burning smell from the vents and inexplicable noises coming from the furnace unit. If these are recurring symptoms, you should call in the HVAC specialists as soon as possible, since the overheating furnace can be potentially life-threatening.
As a homeowner, you may want to investigate why your furnace is overheating. Once you recognize the root issues, you can take proactive steps to stop your furnace from overheating again. Below are six reasons why your furnace is overheating and how to fix these potential problems:
Reason #1: Your furnace is overheating because of its age.
Most furnaces are built to last for up to twenty years with regular check-ups and maintenance work. If you just purchased your home, you may not know when the last check-up was done or even how old the furnace is. When a furnace has significantly aged, it could start overheating just weeks or months after you take possession of your new house.
You should have your furnace checked by a professional to ascertain its age and general condition. If you know that your furnace is reaching the twenty-year mark, start looking into options for purchasing a new furnace. In most cases, you will be better off buying a new furnace instead of maintaining an old furnace that is likely to overheat.
Reason #2: Your vents are the problem.
You may have closed several vents in order to control the temperature in various rooms of the house. If you have too many vents closed, this could potentially cause your furnace to overheat. Since the hot air is trapped with no place to go, it will put a lot of undue pressure on your furnace system. To prevent this, open your vents and turn down the thermostat.
In some cases, your vents might be open, but there is something else potentially obstructing the passage. This has the same effect as a closed vent and may cause the furnace to overheat. You will want to contact a furnace repair professional to look more closely into this problem.
Reason #3: The inner workings of your furnace have failed.
A furnace is a large machine with many parts, some of which are delicate. You may have an overheating furnace if the wiring or any mechanical component came loose, became broken, or simply stopped working. Without the technical expertise, it will be difficult for most homeowners to figure out exactly what broke inside the furnace. This is one of the few furnace repairs that you won’t be able to DIY.
Instead, contact a professional HVAC expert for assistance. The knowledgeable technician can inspect the furnace and quickly analyze which elements have failed. The technician can also identify potential weak links, allowing you to replace the parts and components before they break apart.
Reason #4: Your furnace isn’t being properly maintained.
Your furnace could be overheating due to maintenance issues. Think about the last time you had a furnace maintenance check-up. If these inspections haven’t been occurring on a regular basis, your furnace might have maintenance risks that could lead to the system overheating.
During these furnace inspections, the technicians can identify small problems that are easy to fix in the moment. If left unattended, these issues will escalate over time and cause more dramatic problems in the future. To avoid an overheating furnace, you should schedule regular check-ups about once a year.
Reason #5: Your furnace doesn’t have sufficient airflow.
Keep a close eye on the condition of your furnace’s air filter. If this component becomes too dirty, your furnace can quickly become coated with lint, dust, and other unpleasant materials. When this happens, your furnace may not be able to cycle the hot air as intended. Since there is limited air flow traveling through the furnace, this will lead to the risk of overheating.
Make sure the airflow remains as clear as possible by cleaning or replacing the air filter. This should be done each month. Be sure to replace any filters if they become damaged or too old to perform the job effectively.
Reason #6: Your furnace is short cycling.
Your furnace may start short cycling when the system shuts off before it can move through all the stages of heating. Short cycling often occurs if there is a issue with the heat exchanger or lack of air flow. Often these issues result in the furnace being controlled by its high limit switch and not the thermostat. When this happens, it stresses out the motors and other components of the furnace, which can lead to a furnace breakdown.
You may not even notice your furnace is short cycling at first, so be more attuned to when the system powers on and when it is suddenly turned off. Short cycling could be the result of a complex furnace problem, so you should contact a professional for a deeper diagnosis.