To make a noisy furnace quieter, first identify the sound. For DIY fixes, replace your air filter to stop whistling, secure rattling panels and ductwork with screws or padding, and lubricate the blower motor to reduce friction. For persistent or loud mechanical problems, contact a licensed HVAC professional immediately.
The $5,000 rule is a guideline to help homeowners decide whether to repair or replace their HVAC system. You multiply the age of your unit by the cost of the needed repair. If that number exceeds $5,000, replacing your HVAC system is often more cost-effective.
Try do-it-yourself steps
Change air filter if you hear whistling or whooshing. Look for holes in the ductwork and plug them to stop a whistling sound. Screw a metal plate over a weak area in the ductwork to stop a banging sound. Use a screwdriver, duct tape, or padding to secure rattling ducts.
If your furnace is making noise but still running, here's what you can do safely:
To make your furnace quieter, start by replacing a dirty air filter and ensuring vents are open. For lasting relief, clean the blower motor, insulate the furnace closet, decouple the unit from the floor using rubber pads, or replace metal duct connectors with flexible acoustic ducting.
In short — yes, it can be. A buzzing furnace often points to electrical issues, loose parts, or airflow problems inside your home's heating system. While some noises are harmless, others could mean your furnace is at risk of system failure, a fire hazard, or even a gas leak.
Furnace noise can have a variety of causes, and it's essential to know when furnace sounds should raise red flags. Sounds such as sharp cracks, steady rumbling, high-pitched screams, grinding noises, and continual rattling or vibrations should all be reported and dealt with right away.
The heat exchanger is often considered the most costly part of a furnace to repair or replace. It is a critical component that transfers heat from the combustion process to the air that circulates throughout your home. Over time, heat exchangers can crack due to the constant heating and cooling cycles they undergo.
For example, the Lennox SLP98V Variable-Capacity Gas Furnace is at least 50 percent quieter than competitor's furnaces, making the SLP98V gas furnace the quietest furnace you can buy1. SilentComfort™ is achieved by utilizing variable-speed technology.
5 Warning Signs It's Time for Furnace Replacement
It is completely normal for a furnace to produce a few background noises while running. Common sounds include a dull, continuous humming from the blower motor, a soft "whooshing" or blowing of air through the vents, and occasional clicking when the system cycles on or off.
Blower Fan Still Running
A furnace blower wheel continuing to run after being switched off will cause whirring noises. Check your fan settings and auto-shutoff controls. The fan motor or sensors may need replacing.
A standard furnace lasts between 15 and 20 years on average, though electric furnaces can stretch up to 20 to 30 years. Regular maintenance, such as annual tune-ups and changing your filters every 1 to 3 months, is the most important factor in reaching or exceeding this lifespan.
However, with the passage of the new budget, homeowners now have until the end of 2025 to take advantage of the HVAC tax credits, which include: $2,000 for a qualified heat pump. $600 for a qualified air conditioner. $600 for a qualified gas furnace.
The best time to buy a furnace is during the off-season, specifically late spring (April-May) or early autumn (September-October), when HVAC companies are less busy and offer lower prices, rebates, or promotions. Purchasing in these shoulder seasons ensures faster installation times and better negotiating power compared to winter peak season.
What fails first on a furnace? The most common early failures are the furnace ignitor or flame sensor, as they experience regular wear and tear and are critical to starting the heating cycle.
The national average cost for replacing a gas furnace in the U.S. for a 1,600 to 2,000-square-foot home is about $7,000. However, the cost of furnaces can range widely depending on their size, type, and efficiency, and homeowners can generally expect a new furnace to cost anywhere between $3,800 and $10,000.
Yes, you should highly consider replacing a 30-year-old furnace. Most furnaces have a lifespan of 15 to 20 years. At 30 years old, your system has likely outlived its expected life. It is operating at a much lower efficiency than modern units and presents a significantly increased risk of catastrophic breakdown or dangerous carbon monoxide leaks.
Your furnace may be blowing cold air due to a dirty air filter, thermostat issue, pilot light failure, or a problem with the flame sensor or gas supply.
Banging or Booming Noises
Over time, repeated small explosions can damage your furnace and even crack the heat exchanger, which is a major component of the system. Another possible cause of banging noises is the metal ducts expanding and contracting due to heat. This isn't usually dangerous, but it can be annoying.
A loud furnace is usually caused by a dirty air filter, loose panels, worn-out motor bearings, or a gas ignition issue. The specific noise your furnace makes can help you pinpoint the exact problem.
Stoves and ovens (cooking equipment) are the leading cause of house fires. According to the National Fire Protection Association (NFPA), cooking is the number one cause of home fires and injuries, primarily due to unattended cooking, grease buildup, and human error.
Once the heat exchanger reaches a specific temperature, you'll hear the blower come on. You may hear a fairly loud noise just as the burners light. However, the furnace shouldn't make an overly loud booming sound.
Broadly, heat pumps are the most efficient form of heating. They can be more expensive than a furnace, especially if you purchase a geothermal heat pump. However, geothermal heat pumps are one of the cleanest heating options on the market. A geothermal heat pump can produce 1/6th the CO2 of a natural gas furnace.