11 Different Furnace Noises and What They Mean

As the winter chill settles in, everyone needs the comfort of a toasty home. But with an aging furnace, that sweet warmth can often come with some unexpected noises. Does your furnace make a loud noise when turning on? Understanding these sounds can alleviate some of the anxiety they might bring.

At One Hour Heating & Air Conditioning, we have decades’ worth of experience in diagnosing and solving furnace quirks in locations all across Hampton Roads, Virginia. This will explain the many sounds you might hear from your furnace—from the benign to the potentially troublesome. Armed with this knowledge, you’ll be better equipped to distinguish typical operating noises from those that need professional attention.

The sounds we cover in this blog:

• Banging
• Shrieking
• Scraping
• Buzzing and Rumbling
• Whistling
• Popping
• Humming
• Clicking
• Rattling
• Chirping
• Hissing

Banging

Banging noises are never welcome in the home, especially when emanating from your furnace or if you find your heater making a loud noise. These sounds are usually related to delayed gas ignition within the combustion chamber. When the burners are dirty or misaligned, they fail to ignite gas quickly, causing a small explosion once ignition occurs. Aside from making loud banging noises, this issue can lead to serious safety hazards and should be immediately addressed by a professional.

Shrieking

A high-pitched squeal is a standard alert that the motor within your furnace is having issues. A furnace making a loud noise like this is often caused by a deteriorating belt or bearings that need lubrication. At first, these problems might be simple and inexpensive to fix. However, left unaddressed, they can create greater damages and costly repairs. It is best to contact a certified HVAC contractor to repair or replace any problematic parts.

Scraping

If you hear scraping noises while the furnace is in operation, this is likely an indication that ball bearings are worn or the blower wheel is loose. Both cases need expert attention. To prevent further damage to the system, it’s smart to stop using the furnace until examined by a certified HVAC technician.

Buzzing and Rumbling

A constant buzzing or low rumbling noise may indicate loose or damaged components in the furnace. If not functioning correctly, elements like the blower motor, heat exchanger, or gas burners may contribute to these sounds. A thorough inspection by a skilled professional can ensure all parts are secure and operating safely and preserve the furnace’s performance and longevity.

Whistling

When a furnace begins to whistle, it’s often due to restricted airflow, commonly from a clogged filter. A simple filter replacement might remedy the noise. Otherwise, professional intervention may be necessary to uncover and resolve further airflow issues within the ductwork or furnace itself.

Popping

During the initial heating cycle, you might notice a popping noise resulting from the expansion of air ducts as they adjust to warm air. While usually not severe, aging furnaces may also experience these noises from debris accumulation on gas burners. Regular cleaning and maintenance can prevent these disruptions.

Humming

Though many furnaces generate a low hum, a loud hum can signal a problem with the blower fan or capacitor. Loud humming isn’t just an annoyance—it indicates a potentially serious issue that needs professional diagnosis and repair to avert damage to the fan or related components. If you’re wondering, “Why is my furnace making a loud noise? ” Professional inspection can help identify and resolve these issues.

Clicking

Clicking can mean a broken, jammed, or clogged gas valve. This issue can slow ignition, preventing the furnace from heating properly. In the case of an electric furnace, some components part of the starter system can fail and create strange clicking noises. Luckily, with electric furnaces, you don’t need to worry about gas leaks. However, these clicking sounds require professional attention for your heating system’s safe and proper functioning.

Rattling

Thinking, “Why is my heater making a rattling noise?” Rattling noises may suggest loose panels or screws within the furnace. This sound often emerges as a result of the furnace’s cycles of heating and cooling, which can cause components to loosen over time. While not immediately hazardous, it’s a good idea to address these issues to avoid more serious problems. Tightening any loose parts is an easy solution that can prevent further damage.

Chirping

A chirping noise is usually not a cause for concern, especially when a furnace is used for the first time after a long period of inactivity. It often results from the natural settling of mechanical components. However, if the chirping persists beyond the initial start, it might mean there’s not enough motor lubrication or the proper belt alignment. This simple maintenance can alleviate the noise and keep your furnace running.

Hissing

Hissing sounds emanating from your furnace can be escaping air or gas within the system. This type of noise may originate from a leaking gas valve or a heat exchanger crack, both of which require urgent attention due to potential safety hazards. In the case of oil or gas furnaces, hissing could also suggest air leakage in the ducts, which may cause poor heating and higher energy bills.

Our HVAC Pros Are Ready To Help!

So, now you know the everyday furnace noises and what they mean. Hopefully, this knowledge offers some relief, and you’re all set to prevent minor problems from turning into major repairs.

And remember, always rely on a licensed HVAC professional for inspections and repairs to protect yourself and restore harmony to your home. The professionals at One Hour Heating & Air Conditioning have the experience you’re looking for, and it’s all laid out in our guarantees! If you’re in Virginia and your furnace is singing an unusual tune, contact us at 757-868-7600 or visit us online.