7 Reasons Why Your Furnace Is So Loud: Expert Insights
Common furnace noises like banging, squealing, and scraping indicate issues such as ignition delays, motor problems, or loose parts. Address these concerns promptly to prevent further damage and ensure a safe, quiet furnace operation.
Furnaces are naturally loud appliances. And in mobile homes, the furnace is usually close to the living area. But there are different furnace sounds, many of which are signs of something requiring your attention.
Let’s look at why your mobile home furnace is so loud and how to make it stop before you poke out your eardrums.
You’ll know the difference between a problem noise and a furnace’s usual racket.
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1. Banging and booming
An ignition delay can cause a mini-gas explosion inside the furnace. The bangs and booms come from the gas building up in the combustion chamber when the furnace’s gas burners fail to ignite on time.
When a gas burner isn’t igniting correctly, a clog or gas pressure issue may require addressing.
Do not attempt to fix a gas burner yourself.
You will call a professional, licensed technician to safety check for the source of the banking.
If you disassemble the heat exchanger or burner incorrectly, it can spring a leak into the home.
2. High-pitched squealing
A shriek or squeal is an indicator that there’s an issue with the motor related to the belt.
You can fix the shrieking yourself with the right equipment and tools. Call a professional contractor if you aren’t sure you can replace the furnace belt right.
3. Scraping
Worn-out ball bearings can cause a very annoying scraping sound. But that’s not the only reason.
A blower wheel may be loose, requiring turning the heating off and calling an HVAC specialist.
Why does my furnace sound like a freight train?
The freight train sound from a furnace typically means there’s a problem with the blower wheel.
4. Rumbling
A rattling sound is one of the easiest noises to identify because the sound indicates a loose part somewhere in the furnace.
One part can come loose and cause damage to other furnace components.
You likely need to call a professional technician who has the right tools and equipment to inspect the components of the furnace, including:
- blow motor
- hot surface igniter
- heat exchanger
- gas burners
5. Whistling
A clogged furnace filter will restrict air flow, which leads to a spooky whistling sound.
Replace your furnace filter, and the ghostly noises should go away.
6. Howling
Damaged furnace insulation can cause a howling noise because air is getting through and around it.
You can DIY the fix using insulation foam spray or expanding foam around the furnace fan flower.
7. Humming
While the hum is usual, a noticeable loudness change may mean something bigger is happening.
A severe blower fan or capacitor issue can cause a furnace hum to become noisier.
A licensed contractor can check out the motor blower and make the required repairs.
What should a normal furnace sound like?
First, a pop and click will signal that the furnace has ignited and is on.
Once it’s on and settles, a low hum will emanate as long as it runs.
You may hear a slight crackle when the metal parts of the furnace begin to cool after a heating cycle.
Any noise beyond a hum can signal a big furnace problem.
How can I reduce the noise in my mobile home furnace?
Locate and fix any loose parts
Most loose parts like belts and bolts are easy to narrow down and replaceable.
While you’re in there, check all the bolts and belts and ensure they are tight and not damaged.
Use foam spray insulation
Even the smallest crevice or gap in the furnace insulation can cause whistling and howling.
Foam spray insulation is a quick and straightforward way to seal up the offending parts.
Fasten the furnace motors
You can fasten a furnace to the housing using screws to reduce some of the noise pollution. But rule out any other problem before you attach the furnace motors.
Check out the current fastener for any damage. A faulty furnace fastener can be the cause of the furnace noise.
Lubricate the blower fan
Sometimes all a noisy blower fan needs is a little lubrication.
To resolve the commotion, you can try applying a furnace lubricant to the bearings.
If the sounds don’t stop, it might be time to replace the blower fan.
Adjust the fan speed
Lowering the furnace noise level is as easy as turning down the fan speed.
You can experiment with up and down to find the balance between the right amount of furnace heat and the wrong amount of furnace loudness.
Call a professional furnace fixer
Many furnace problems require a licensed professional. It’s dangerous to repair anything that uses natural gas unless you have the proper training, equipment, and tools.
Applying lubrication, tightening bolts, and changing furnace filters are typically safe for a mobile homeowner.
Furnace safety
A furnace doesn’t have to make noises for there to be a significant issue.
Most carbon monoxide leaks are sometimes caused by cracks in the heat exchanger, which is a silent problem.
Carbon monoxide has no smell, color, or taste, and you can’t hear most leaks because they are tiny.
You must have a working carbon monoxide detector if you have a furnace to avoid the dangers of carbon monoxide poisoning.
Frequently Asked Questions
How do you fix a noisy furnace?
- tighten loose screws and bolts
- seal up crevices with foam spray insulation
- check fasteners
- use furnace lubricant
- adjust fan speed
- call a licensed furnace technician
Should I be able to hear my furnace?
Some furnace noise is normal, especially in mobile homes. If it grows louder, or there are new, disturbing sounds, shut the furnace off and call a professional.
Why is my furnace louder than normal?
If the noise level of your furnace changes suddenly, it can mean that there’s a big issue with the blower fan or capacitor.
Why is my furnace blower motor so loud?
The biggest culprit for a noisy furnace blower motor is wear and tear. The motor has bearings that overheat and age over time.
Can you adjust the fan speed on a furnace?
You can adjust the fan speed on a furnace by cutting the power and removing the cover to access the control board. By adjusting the pulley on the blower driver motor, you can increase or decrease the blower speed.
What does a bad furnace capacitor sound like?
A bad furnace capacitor can be identified by the presence of humming noises. When the capacitor is not working correctly, it hinders the flow of electricity to the furnace’s fan motor, resulting in a peculiar low-humming sound when the furnace is initially turned on. This humming may continue for a few seconds before the furnace starts blowing air.
Why is my trailer furnace so loud?
My trailer furnace is loud because the high-speed fan generates most of the noise, which is then amplified by the enclosure it is placed in. To reduce the noise level to a dull roar, you can follow this guide that explains how to use soundproofing material and a simple airflow technique.
What to do if your furnace is making a loud noise?
If your furnace is making a loud noise, it is important to address the issue promptly. Unusual sounds such as banging, rattling, whistling, or screeching indicate a problem that needs to be resolved. It is recommended to contact a furnace technician to inspect your furnace if you hear unfamiliar noises.
Why does my furnace sound like a freight train?
Your furnace is making a sound similar to a freight train because there is likely a problem with the blower wheel.
When should I worry about my furnace noise?
You should worry about your furnace noise when you hear an unusual vibrating or whining sound, as it could be a sign of a furnace problem that requires a technician’s inspection. Additionally, a loud humming noise may occur when the furnace burners light during colder temperatures. To reduce this noise, you can adjust the burner flame by turning the off/pilot/on control.
Should you be able to hear your furnace?
You should be able to hear your furnace on a normal day as it starts up, turns on, and then turns off. Some noise from the furnace is to be expected, but it should never be disruptive.
Can a dirty furnace filter cause a humming noise?
A dirty furnace filter can cause a humming noise. When the filter is dirty and blocked, it forces the motor to exert more effort in pushing out air. To prevent this issue from happening again, it is important to regularly check and clean the filter. If your furnace blower motor hums upon switching it on but fails to turn, it is possible that the capacitor has been damaged.
What does a bad furnace transformer sound like?
A bad furnace transformer can be identified by the sound it produces. When the humming of the transformer becomes excessively loud or starts vibrating, it indicates a problem. If the sound persists and becomes too loud, it is likely that you have a faulty transformer. This issue can quickly affect the functionality of your home’s heater.
Why is my heating unit making a loud sound?
The loud sound from your heating unit could be caused by loose parts in the motor or blower, resulting in banging, thumping, or rattling noises. If the banging becomes louder, it may indicate that something that was loose has now broken off. Additionally, humming or vibrating sounds could suggest loose parts or an imbalanced motor.
Why is my furnace blowing so loud?
My furnace is blowing loud because it is working too hard, which can result in loud air or motor noises. This issue is often caused by a dirty or clogged air filter, preventing the furnace from effectively pulling in air. To resolve this noise, simply clean the filter, which is an easy solution.
Why does my furnace sound like a jet engine?
The reason your furnace sounds like a jet engine is that blocked or closed vents can create higher sound pressure when the furnace blower motor and fan force air through, leading to a noise resembling that of a “jet engine.”
