Your furnace will always make more noise than your air conditioner. The reason for this is fairly obvious since the furnace is inside, and the AC unit is outside the home. Hearing some noise whenever your furnace runs is normal. However, if your furnace is suddenly much louder than normal or you hear any banging, rattling or squealing noises, this indicates that there is some issue with your furnace. With that in mind, here are five issues that cause furnaces to be much louder and what you can do to fix them.

1. Dirty Air Filter

This is the most common reason and also the easiest one to both prevent and fix. During the winter, when your furnace runs all the time, the filter can quickly become clogged with dust, hair and debris. A dirty air filter drastically restricts the airflow coming into the furnace, and this can lead to loud whistling noises whenever your furnace runs. To prevent this issue, all you need to do is regularly inspect your air filter and replace it whenever it begins to look overly dirty. In general, you should always replace the filter every one to three months or wash it if you have a reusable filter.

2. Worn-Out Blower Motor or Belt

If your furnace and HVAC system are fairly new, you likely have a direct-drive blower motor. This type of motor uses bearings to power the motor and spin the blower wheel. These bearings can eventually begin to wear out and start to make a loud grinding or squealing noise whenever the fan is running. The same issue can also occur if you don’t make sure to have the bearings lubricated every year. In either case, you will need to have one of our HVAC technicians inspect the blower motor. If the bearings are worn out, the blower motor will need to be replaced.

If your furnace is an older model, the blower motor may be belt-driven instead. As the motor ages, the belt can start to wear out or become misaligned. When this happens, it will also make a loud squealing or screeching noise, similar to a worn-out belt in your car. Again, the solution to this issue is to have one of our furnace technicians replace the belt.

3. Damaged or Misaligned Blower Wheel

The blower motor works to spin a large metal wheel, and this is what circulates air throughout the HVAC system. There are times when the vibrations cause the blower fan to become loose or the blower wheel to move out of alignment. These issues will result in a loud grinding noise like metal scraping on metal. If you hear this sort of noise, you need to have the blower wheel inspected immediately and realigned or else the grinding could cause serious damage.

4. Dirty Ignition Burners

Your furnace’s ignition burners need to be cleaned once a year, and this is one of the many reasons why you should always schedule an annual heating tune-up. Over time, the burners can become coated in dirt and grime and prevent the furnace from igniting properly.

Dirty burners can cause a delay in ignition, which usually results in a loud booming noise whenever the furnace first turns on. An ignition delay can allow the combustion chamber to fill with gas before the burner is lit, which results in a loud fire burst or explosion once the gas lights. This problem can be quite serious and create hazardous conditions, which is why you should call us immediately.

5. Cracked or Faulty Heat Exchanger

This is the worst of all furnace problems and will usually mean that you need to have your furnace replaced. The heat exchanger is what allows the heat energy generated by burning gas to be transferred to the air flowing through the furnace.

If your airflow is restricted due to a dirty air filter or other issues, it can allow heat to build up inside the unit and potentially cause the heat exchanger to crack. This problem is extremely serious. If the heat exchanger is cracked, it can allow carbon monoxide to escape and flow into your ductwork.

A cracked or faulty heat exchanger often results in the furnace making loud rattling noises whenever it runs, and this is another problem that you should have checked out immediately. If you do hear any rattling noises, you should turn your furnace off and not use it until you can have it inspected.

If your furnace is making any loud or unusual noises, the expert HVAC technicians at Fire 'n' Ice Heating & Cooling, Inc. can inspect your heating system and determine what is causing the issue. We service and repair all models of furnaces from every manufacturer, and we also carry a range of new residential and commercial Carrier furnaces for buildings of any size. Our team works on air conditioners as well as air purifiers and other indoor air quality equipment. If you need any furnace service in Downers Grove, call Fire 'n' Ice Heating & Cooling, Inc. today.

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