Usually, it's because the bearings of the motor need to be lubricated or replaced entirely. If this is happening, you'll notice how much louder and more howl-like noises get over time until finally, they begin howling through your home. Fixing howling noises caused by a noisy blower fan is pretty simple.
If the fan is noisy because it is loose in its mount, then that is dangerous. If the blades are loose and making noise, that's dangerous too. On the other hand, if it's just a noisy motor, that is not dangerous in itself, as long as it does not overheat. Or, maybe the blades are unbalanced. If so, just balance them.
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.
Turn off power to your heating system. Open the panel to the blower compartment so you can see the fan belt and motor. Check for signs of fraying and wear – a damaged fan belt needs to be replaced. If the belt is loose, it needs to be tightened – there shouldn't be more than a half inch of give in either direction.
If your blower motor is experiencing some issues, you may hear a high-pitched squeal or whistling sound. You may also experience rattling and loud screeching noises. The motor blower pushes warm air out of the furnace through the ducts into your home.
Find and Replace the Loose Parts
If there is a loose part, such as the belt or bolts, it can cause the blower to shake and howl. Check all belts and replace any that are damaged or worn out. Also, check for loose screws in both fans and vents and tighten them if necessary.
Overheating. Blowers with worn-out parts are more prone to overheating. This can damage other components in the system, and it can even be a fire hazard if it's not addressed. It can also cause your system to shut down, leaving you without any heat or air conditioning.
If you hear loud humming, then you can probably take care of it by cleaning the blower fan. Extreme cases may mean you have worn bearings that need replacement. The friction created results in more current drawn. Replacing the fan altogether might be necessary if you find it is damaged.
Grinding and scraping furnace noises usually point to dry bearings within the furnace blower motor. These bearings need regular lubrication to maintain proper function. If you have a preventive maintenance plan with Estes Services, your technician handles this during an Atlanta furnace maintenance tune up.
Blocked or closed vents can cause increased sound pressure as the furnace blower motor and fan push air through, resulting in a “jet engine” sound.
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.
Fans can fall, but that is simply because they haven't been mounted properly. Wobbling fans look alarming, but don't fall because of the wobble. Bits may come off, such as the light cover, but the fan itself will stay put. The wobble is not the result of loose mounting, but misaligned blades.
A fan makes more noise if its parts are loose or not working properly. There might also be something wrong with the firmware for the hardware component that's running the fan.
If the sound is louder than typical and lasts longer than normal, it can be a sign of a problem with dirty burners, high gas pressure, or a malfunctioning heat exchanger, all of which could compromise the equipment's functionality and safety.
Perform Regular Maintenance: Clean fans and nearby components regularly to prevent dust buildup, which can cause imbalances and increase noise. Apply proper lubrication when needed. Use Noise-Absorbing Materials: Incorporate foam or acoustic padding around the fan or in the housing to absorb and dampen sound.
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.
A failing blower motor may emit unusual sounds. This may sound like screeching or squealing if it has bad bearings. You may hear a rattle or a banging sound if something inside the motor has broken or come loose.
A loud knocking noise coming from your furnace might indicate old, dirty burners or a faulty gas valve. Loud knock-like bangs are often a standard indicator of repetitive gas ignition. When furnace burners are covered in rust or grime, they don't efficiently heat the air or the gas around them.
Here are several common causes of a noisy bathroom fan:
There is a lack of proper lubrication. The fan is loose within its housing. The fan has come out of alignment with the housing. There are loose or damaged fan blades.
As reported by the National Fire Protection Association (NFPA), heating systems like furnaces are a major factor of home fires, leading to almost 50,000 blazes, 500 civilian deaths and more than $1 billion in significant property damage each year.
If you're hearing strange noises coming from your furnace blower motor, it likely indicates a problem that needs attention. A noisy furnace blower motor can be caused by a variety of issues, ranging from minor to severe.