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My Heater Is Making Noises: What Is Going On?

a home where the heater is making noises

Heater making noise? If so, it may or may not signal a problem that needs attention from a heating and cooling specialist. Heaters can make all kinds of funny, unexpected sounds in the winter, like rattling, whistling, humming, chirping or banging noises. If your heater starts making a strange sound, what might it mean?

Any strange noise coming from your heater should be investigated since there’s a chance that it means something is wrong. If you wait instead of having the issue diagnosed, it could become a bigger and more expensive problem down the line. To avoid this, it’s almost always best to go ahead and address the issue as soon as possible.

Here’s what may be happening when your heater is making unusual noises.

A Rattling, Clanking, Knocking or Banging Sound

Rattling, clanking, knocking or banging sounds can indicate a loose or broken part somewhere in the heating system. A loud banging sound should be looked at as soon as possible by a heating professional, since it can be a sign of something that has gotten disconnected or damaged within the system, possibly related to either the ductwork or the blower motor.

A Bang or Boom Sound

A bang or boom could be coming from the ductwork, vents and other metal parts expanding and contracting as the heater cycles on and off. This is normal in many cases, and may not be a serious issue. But it’s also possible that the banging sound indicates something more severe, such as a delay in the gas ignition that could damage the heater. If your heater makes a loud bang or boom, it’s a good idea to get a proper diagnosis from a heating professional to make sure it’s nothing serious that needs attention.

A Screeching or Squealing Noise

Screeching or squealing noises could mean your heater’s blower motor is having bearing problems or there’s an issue with the belt. If this is the case, the bearings may need to be lubricated, or the belt might need replacing. These aren’t usually complicated fixes; a licensed heating professional can handle this quickly and easily.

A Chirping Noise

Chirping noises that happen when you turn the heater on but then stop after a few minutes may not be a problem. But, it’s still a good idea to have your heater checked out in case the noise is coming from the blower motor belt.

A Rattling or Vibrating Noise

Rattling or vibrating noises could mean something simple like a loose panel, which just needs to be tightened. However, it could also signal something bigger or a more significant issue. So, again, it’s a good idea to get your system checked out.

A Humming Noise

A humming noise could indicate that your heater’s blower motor needs lubrication, or that the capacitor is damaged and the motor needs to be replaced.

A Whistling Noise

A whistling noise could be coming from your ductwork. If you hear this type of sound when you turn on your heater, it’s a good idea to arrange for a licensed technician to come out to see what might be amiss.

Many of the above noises and potential problems are related to issues with the heater’s blower motor or its belt. If your heater’s blower motor needs to be repaired or replaced, the heater will probably have other symptoms of a problem, along with making strange noises. There might be very weak airflow coming from the vents, for example, or no airflow at all. The heating system could also overheat, which usually causes a burning smell when you turn on the heater. The heater also might stop working altogether. This can happen due to an automatic shutdown within the system that is designed to prevent bigger problems, such as electrical hazards.

The same is true for other components of your heating system that may be damaged or not working optimally—a funny noise is usually not the only symptom. If you notice a funny sound coming from any part of your heater, ductwork or vents, consider whether the heating system as a whole seems to be having issues. Has your home seemed as warm as it normally does in the winter? Have your heating bills been about what they usually are? Or, are your electric bills more expensive? Does the heater seem to run in its usual on-off cycles? When you consider how the system seems to be working as a whole, you may realize there are other signs that it isn’t operating correctly and needs to be looked at by a professional.

While the average homeowner may be able to handle some fixes around the house, typically issues with your air conditioner or heater are best left to licensed professionals. These trained technicians have the experience, tools and know-how to quickly pinpoint the source of the problem and recommend a solution.

It’s also good to remember that having your heating system serviced annually by a specialist is the best way to catch any types of these issues early on. Ideally, this should be done in the fall before the cold weather hits. People who don’t have their heaters maintained can encounter expensive problems in the winter, right when they most need their heater to work correctly. Having an annual maintenance agreement in place that includes having a heating specialist to inspect your heating system once a year will go a long way toward keeping your heater working at peak efficiency. It will also help to extend its life as long as possible. Professionals have the training to spot heating problems that are just beginning to develop. And, they can address them in a timely manner so they don’t get even worse over time.

Two areas that could be having problems that would result in strange noises coming from your heater are your ductwork and your furnace’s blower motor. Keep reading for more information about these two important parts of your heating and cooling system.

an air vent blowing warm air through a home

What to Know About Sizing Ductwork

Does your heater work as well as it should to distribute warm air throughout your home and keep it comfortable during the colder months of the year? If not, it’s possible that your home wasn’t installed with the right size of heating ductwork. Just as it’s not good to have a heating and cooling unit that’s the wrong size for your house, the wrong sized ductwork can also cause heating and cooling problems in your home.

Sizing ductwork is a tricky calculation, so it can be tough to determine what the right size is for your particular home. These complicated calculations are best left to heating and cooling professionals, who have the knowledge and tools needed to consider all the variables and determine your home’s particular needs.

Ductwork sizing is based not just on the square footage of your entire home, but also on the size of each individual room. Professionals can use what’s called a load calculator to determine how much heat any given room in your house will need based on its square footage as related to cubic feet of airflow per minute, or CFM. Once they’ve calculated the CFM for each room, that information is compared to your furnace’s output capability based on its size in tons to determine the best duct size for each space.

When the wrong size of ductwork is installed, it can lead to a system that doesn’t work optimally and wears out too soon. Ductwork that is too small causes an increase in static pressure, which makes for noisy ducts (another reason not to ignore rattles, whistling or banging sounds, or vibration coming from your ducts!). Small ducts also cause the heater to run too hard as it works overtime trying to push enough warm air into the rooms of your home. Ductwork that is too big can also lead to an overworked system and rooms that aren’t warm enough, as not enough heated air pushes through the registers to heat the rooms of your home.

A licensed heating specialist can inspect your system and make the proper calculations to determine your home’s square footage, the CFM for each room in your home and the static pressure of your heating unit. Together, these calculations will help the heating specialist determine the right length and diameter of ducts for your particular home and heating system, to ensure that you stay warm through the winter as your heater works at peak efficiency.

a kitchen where you can hear noises from the heater because the furnace blower motor is not working

Signs Your Furnace Blower Motor Is Not Working

A furnace blower motor not working correctly might be something that you notice right away, as your heater makes funny squealing or humming sounds, your heater smells or there’s low airflow coming from your vents when you turn on the heat. But there could also be subtler signs that there are problems with your furnace’s blower motor, such as your heater cycling on and off too often, or your energy bills are unusually high.

The good news is, if the furnace blower motor is not working correctly, it’s often a relatively simple fix for a heating and cooling specialist, who should be able to handle the problem quickly. A heating specialist can also determine if there’s some other issue with the heating system that needs to be addressed. In most cases, a licensed technician can give you the most accurate diagnosis of how well your heating system is functioning, and can bring the right experience, tools and skills to resolve any heating problem your home may be experiencing.

ABC Can Make Your Home Comfortable Again

Whether you are concerned about strange noises coming from your heater or you’re looking for routine heating maintenance, ABC Home & Commercial Services can help. Our highly trained professionals know all the ins and outs of every make and model of heater and can offer you honest advice on what your best next steps are. And, for those heating problems that just can’t wait, like a heater that won’t turn on, we offer 24/7 emergency services.

Tom Riggs

Tom Riggs is the Division Manager for Mechanical Services, overseeing sales and operations for HVAC, Plumbing, Electrical, Appliance Repair and Water Quality for all ABC Austin branches. He joined ABC in 2014. Before ABC, he was an HVAC Service Technician, HVAC Comfort Advisor/Sales and Operations Manager. Tom attended Universal Technical Institute. He's an avid outdoorsman and enjoys country living with his wife and two sons.

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