Tuckers Air Conditioning, Heating & Plumbing Blog

What’s That Noise? Sounds You Should Not Hear from Your Furnace

One of the easiest ways to identify a furnace malfunction is by paying attention to the sounds your unit makes. There are some quiet sounds that are a normal part of everyday operation. But loud or persistent noises can be a red flag that something is going wrong inside your furnace.

Some sounds are more serious than others, but they all deserve immediate attention so they don’t have a chance to worsen. You can keep reading to learn more about the sounds that indicate you need to call and schedule heater repair in Frederick, MD.


Booming is one of the more alarming sounds you can hear coming from a furnace. This is especially true if you have a gas furnace. Booming can indicate that too much gas is building up in the chamber before ignition happens for combustion. When the flame finally ignites, the amount of gas creates an explosion that adds pressure to the heat exchanger. 

Eventually, this excess pressure can cause the heat exchanger to crack, leaking carbon monoxide gas into your home. Unfortunately, once your heat exchanger cracks, it cannot be repaired. This means it is increasingly important to quickly address a booming sound coming from your furnace.


Rattling can happen for a number of reasons. It can come from the ductwork attached to your furnace, or it can happen when small components inside your furnace get loose and tap against another surface. 

If you hear rattling for just a few seconds when your furnace first turns on, this can be completely normal as the thin metal ductwork adjusts to temperature changes. But if rattling is persistent, that’s when it’s a red flag that needs to be addressed.


Like rattling, if your furnace clicks a couple of times when it first turns on, this is completely normal. However, if the clicking is persistent and it seems like your furnace is struggling to turn on for a heating cycle, that can mean that there is an issue with the igniter. 

If it is taking too long to light, too much gas can build up inside the chamber ahead of the beginning of a heating cycle. This is dangerous because it causes the booming sound that we mentioned earlier in this post. But sometimes clicking means that your heater is not turning on at all. Your furnace may not be operating at all to heat your home, resulting in poor indoor air quality and low temperatures. 


Squealing can happen if a belt begins to loosen up and causes an imbalance inside the furnace. Squealing can also happen if there’s an issue with the bearings in the motor. Over time, dust and dirt can build up inside of these bearings and dry up lubrication, resulting in a squealing sound when the motor operates. 

If you catch these problems early, the solution is as simple as replacing the belt or cleaning out the bearings. But if the squealing sound goes on for too long, it can result in lasting damage inside of your furnace that leads to more expensive repairs.

Ready to get started? Call or click to talk to a team member at Tucker’s Air Conditioning, Heating & Plumbing today. Your Whole House Approach to Comfort.