The holidays are just around the corner, bringing joyous sounds of merrymaking and Christmas carols. So, it can be unsettling if what you hear instead are “ghost-like” banging or whistling noises at home.
While you likely don’t have to worry about those noises being paranormal, you still need to investigate them. They could be coming from your furnace, signaling a heating system issue.
You don’t want a broken furnace, especially not with Texas possibly having an unseasonably cold and stormy winter this year.
So, in this guide, we’ll talk about normal and abnormal furnace noises and what they mean. We’ll also discuss the steps to take if you hear them and how to prevent them, so read on.
Furnace Noises and What They Mean
You’ll usually hear a minor clicking or popping sound when you turn your furnace on for the first time.
The initial click is likely from your system’s ignitor. It can produce this sound as it lights the burner.
On the other hand, a few pops here and there can come from your system’s metal parts. They can result from the metal expanding as it heats up.
Those sounds should mellow down or disappear after a few minutes. You may then hear a dull thrumming as your system kicks into gear.
But if your furnace makes any of the following noises, take them as a sign of an abnormality.
Repetitive Clicking
This sound often results from a furnace ignitor being unable to ignite or keep the pilot light lit. As a result, it will keep trying to do its job, hence the repetitive clicking.
The pilot light may fail to ignite if its tube is dirty or it doesn’t get enough gas. Not receiving enough gas could be due to a leaking or clogged gas line.
Continuous or Loud Popping
Dirt and debris build-up in a furnace burner can cause continuous popping sounds. The particles themselves can produce these noises as they burn. Conversely, it could be due to the gas building up and then popping as it finally ignites.
Wheezing
If you, a loved one, or a friend has respiratory allergies, you likely know that these can cause wheezing. You may also be aware that this is often due to allergens and pollutants obstructing the airways.
But did you know that air contaminants can also make your furnace wheeze?
That usually occurs when filters get so dirty they already impede airflow. As a result, the furnace has to work harder to “suck” air in through the clogged filter. This difficulty getting air in can make it sound like it’s wheezing.
Grinding or Scraping
These noises typically result from metal parts grinding against each other.
For example, dry and worn bearings can cause gears to rub against other metal parts. Another is a loose blower wheel scraping against its case.
Booming
As with loud popping sounds, booming noises can indicate dirty burners. However, it may also mean that there’s far more debris in the burners, causing more gas to build up. So when that vast amount of gas finally ignites, it can go “boom!”
Booming noises can also signal that your furnace’s heat exchanger has cracked. This is dangerous, as a cracked heat exchanger can leak toxic gases into your home. One of these is carbon monoxide (CO), which is poisonous and deadly.
A cracked heat exchanger can cause booming noises as its damaged part contracts and expands.
Hissing or Whistling
If you hear this and a rotten egg-like stench permeates the air, you likely have a natural gas leak.
Natural gas, in its natural state, is colorless and odorless. For this reason, gas companies mix it with mercaptan, an odorant, to make it easier to detect. This is vital as natural gas leaks can cause poisoning, fires, and explosions.
What to Do When You Hear Furnace Noises
Booming sounds that you suspect are from a cracked heat exchanger can be a heating emergency. The same goes for hissing/whistling accompanied by a rotten egg-like stench.
If you experience these symptoms, please switch your furnace and gas valve off ASAP. Then, quickly get everyone, including pets, to leave the house and open as many windows as possible, if you still can. Once you’re safe outside, call your gas company and a reputable HVAC company near you.
If your furnace is only wheezing, you can try to replace its air filter. If this doesn’t help, or your system makes other loud, weird noises, have an HVAC expert inspect your system.
How to Keep Furnace Noise Down
The best way to keep your furnace from making a racket is through seasonal HVAC check-ups and tune-ups. These are comprehensive programs designed to maintain the peak performance of comfort systems.
For furnaces, a regular maintenance program includes the following:
- Thorough inspection and cleaning of the system
- Lubrication of all moving parts
- Checking and tightening all connections
- Adjusting the blower parts
- Testing electrical components and controls
- Confirming the heat exchanger’s state
- Replacing the air filter
- Calibrating the thermostat
- Checking the system’s overall efficiency and performance
- Monitoring carbon monoxide levels
As you can see, many of the steps above deal with the top causes of furnace noises. That’s why regular system maintenance can prevent them from happening in the first place.
Ideally, you’d want an HVAC expert to tune up your system every fall. This way, the pro can catch and address problems before the peak heating season. As a result, you and your loved ones can stay warm, cozy, and comfy throughout winter.
Stop Those Furnace Noises
Now that you know more about furnace noises and what they mean, you can determine if your system is making normal or abnormal sounds.
If it’s the latter, try replacing the air filter first. If that doesn’t help, give us a shout here at Best Air Conditioning and Heating. We’ve been in business since 1983, proudly serving the Greater Lake Livingston, TX, and surrounding areas.
Contact us today for all your HVAC concerns, whether you need help with a noisy furnace or a tune-up. Our HVAC specialists can take care of it all.
