If you notice that your furnace is acting strangely, it’s an indication that something may be wrong. Perhaps the unit is only blowing cold air now, and you can’t get the heat that you need? There are many signs that can warn you that your HVAC system is about to fail when you need it most. In this article, we will look at four common furnace problems that you can detect with no formal training.

  1. A Loud Metallic Scraping Sound

This is a loud noise that sounds like metal grinding against metal. This is likely to be a problem with the blower wheel, and if you hear it, you need to turn off the furnace straight away and call a professional HVAC engineer to investigate. There could be a number of causes; the blower wheel could have worked loose, and if it’s not damaged too much it could be tightened back into place. If the blower is broken, it will need to be replaced entirely. The motor blower mount could have broken, and this is causing the blower assembly to shake and scrape other parts.

  1. The Furnace Starts with a Loud Pop

If you turn your furnace on and you hear a loud pop or bang, there could be a problem with the furnace burner or the ignitor, or it may be an air duct issue.

If the furnace burner or ignitor is dirty, it can prevent the burners from igniting when the furnace is turned on. There may be a delay, and the bang that you can hear is the accumulated gas igniting. Obviously, this is a serious issue. The last thing any homeowner needs is a furnace that cannot ignite gas correctly. If any of these small explosions cause a crack in the heat exchanger, it can result in a carbon monoxide leak. This is also dangerous, and it will also mean that the heat exchanger has to be replaced and that is expensive.

Air ducts that contract or expand when the blower in the heating system starts up can make a similar sudden bang sound. This can be particularly loud if the home is fitted with metal air ducts and it could be a symptom of three problems, they are: a clogged air filter, an obstructed vents and/or an undersized duct.

  1. A High Pitched Whine

If you hear a noise like a high pitched persistent whine when the furnace is running, it could be a number of problems. If you’ve recently had the blower motor replaced, the unit could be flawed, and it will need replacement. There could be a blower belt issue; it may have become loose, or it’s simply worn, and it needs to be replaced. The shaft bearings may need to be lubricated with oil, and this is causing unwanted friction and the accompanying noise. All of these issues can be detected before the heating season begins with a comprehensive service carried out by a certified HVAC technician. This will ensure that your heating system is ready to run and there will be no downtime to fix these problems when you need to heat your home.

  1. The Heating System is Blowing Cold

There are a number of reasons why your heating system could be blowing cold instead of warm air into your home. Let’s take a look at the three most common causes that you need to explore first.

The first thing that you need to check is the thermostat, this may sound strange, but the thermostat acts as the brain of your heating system, and it’s an excellent place to start. Check that the thermostat is set to “Auto” and not the “On” setting. If the system is set to “On,” then the system will continuously blow air even if that air isn’t being heated. This will create a steady flow of cold air into the home that you want to heat. Setting the thermostat to “Auto” will ensure that the heating system will only blow air that has been heated first.

If the thermostat is set to “Auto,” it’s time to take a look at the air filters. The air filters in your system should be changed every month to prevent them from becoming dirty and clogged. If they do become clogged, they could restrict the flow of air into your furnace. When there isn’t enough airflow, the furnace can easily overheat and then it will shut down automatically as a safety precaution. Changing the air filter is a simple task, the details on how to do this should be in the owner’s manual for your specific system.

If the ductwork has any connection problems or leaks, it can also cause a loss of heating performance and cold air. This can even happen with a brand new heating system if a duct connection has been knocked loose or if the installation is poor. The gaps in the ductwork will allow the treated air to escape and cold air to enter the ducts. The heating system will be forced to work harder to compensate for the differences in temperature. This unnecessarily costs money for the heated air that escapes and for the extra energy used by the heating system.

How to Keep Your Furnace Running Well

We rely on our furnace to keep us warm during the heating season and if the system fails our indoor comfort will suffer. Let’s take a look at the best way to avoid these common furnace problems from developing in the first place.

The first thing that every homeowner needs to do is to schedule an annual maintenance check for their heating system before the start of the heating season. A certified HVAC technician will be able to identify any minor issues before they turn into larger problems. This will help you to keep your system running well and reduces the chances of an unexpected fault. A well maintained system is also more energy efficient so you can save money and enjoy trouble free heating.