Normal Furnace Noises Sometimes there is a little bit of a pop or click as the furnace fires up, then the
In most cases, the humming is normal and stems from the draft inducer motor or the furnace blower motor. The draft inducer motor hums or cycles on when the thermostat calls for heat. The blower motor hums as it cycles air through the property. It is possible the humming can stem from an electrical issue.
There are a variety of problems that can cause your furnace to produce loud noises. Types of noises such as scraping, banging, whistling, and popping may be a sign of a loose part, cracked heat exchanger, or dirty gas burners.
On a normal day, your home's furnace might make a little noise as it starts up, when it's turning on, and then when it turns off. You can always expect to hear some noise from the furnace. The thing about this noise is that it should never be disruptive.
At times, it may sound like an off-balance washing machine; at others, you may hear noises resembling something more like that of a jet engine. If you notice your furnace making a rattling or rumbling noise, or other major changes to the way it typically sounds, you're not crazy.
The Average Furnace Lifespan
A well-maintained furnace can last at least 15 to 20 years, but completing annual maintenance and being diligent with repairs can extend its life even longer.
Check the thermostat settings.
The furnace will not come on unless the ambient temperature drops below the setpoint. To test the furnace, temporarily set the thermostat five to ten degrees higher than you normally would to see if it comes on, then return the thermostat to its normal setting when the test is complete.
In order to maintain a comfortable home environment and reduce energy consumption, it's important to ensure your HVAC system is running at an optimal noise level. Ideally any appliance or HVAC system should never create sound louder than 60 dB inside your home.
If your furnace is making an obnoxious noise, it's likely because the furnace blower motor is turning on and off as part of normal heating furnace cycles. Make sure your thermostat is set properly to the desired temperature and off when you don't need heat (like overnight).
One of the most common furnace problems is a malfunctioning thermostat. A sure sign your thermostat isn't working properly is if your fan is constantly running. This will cause your thermostat battery to run, and cause your furnace to work inefficiently.
Rattling (Inside the House), Clanking or Banging
Like “thwapping,” these sounds could be related to the furnace's blower assembly or motor, and are likely due to something being either loose or broken. If you hear louder banging sounds when the blower is running, shut the system off until you can get help.
First, know if you have a gas, electric or oil furnace. Electric furnace installation tends to be the least expensive, ranging between $3,000 and $7,000, according to HomeAdvisor. Installing a natural gas furnace falls in the range of $3,800 to $10,000, and an oil furnace ranges $6,750 to $10,0000.
Over time, normal wear and tear can cause the furnace motor to start squealing, grinding, buzzing, or whistling sound. Here are some of the most common culprits behind furnace motor noise: Bearings wear out – Bearings allow the blower wheel to spin smoothly.
A low rumble is a normal sound when your gas or oil-fired furnace kicks on. However, if that rumble is louder than usual—or lasts longer than usual—this could indicate a very serious problem with your burner.
While costs can vary, homeowners can typically expect the following range: Standard Blower Motors: These might cost between $400-700, excluding labor. Advanced Multi-Speed or Variable-Speed Motors: These are generally more expensive, with costs ranging between $650-1250, not including labor.
Loud Bangs, Rumbles, Knocks, or Booms
Loud noises like this are a sign of a build of gas in a furnace. The noise you hear can mean your heat exchanger is at risk of cracking. Even worse, it's a sign that something dangerous could happen if you continue to use your heater.
It's normal to hear a noise as your furnace starts, especially in old furnaces. This noise could be a product of your furnace igniting and working correctly. An initial pop or click as your furnace turns on is entirely normal, as your furnace should then settle into a dull thrum as it kicks into gear.
While all furnaces generate some ambient noise, they run quiet enough not to be disruptive most of the time. However, loud buzzing or humming can indicate various mechanical or electrical problems, either when the furnace starts up or throughout its operation.
A gas furnace should have a vibrant or bright blue flame. When you see a weak and wavy or flickering flame, this indicates gas is not being completely burned. Pilot light color changes are another indicator that carbon monoxide is not venting away from the system safely.
A furnace inspection costs an average of $80 to $100. Your cost may increase if more furnace repairs are needed, or based on the specifics of your HVAC system. If detrimental issues are uncovered, you'll be quoted for the repair or potential replacement of your HVAC equipment.
For people taking a proactive approach, doing a furnace replacement during the “shoulder seasons” of spring and autumn may offer lower prices, shorter lead times, and a better selection of products and service appointment availability.