It’s about that time of the year when the weather cools off, and it’s time to turn the furnace on to keep your home warm. If your furnace starts making peculiar noises, it could be a sign of a bigger problem. There’s also a chance it’s normal. Understanding these furnace noises and what they mean is crucial for maintaining your furnace, making sure it’s safe, and keeping your home warm.
I’ve been working on furnaces for years now, and I’ve heard them make all kinds of noises. In this article, we are going to go through the different noises and give an explanation of what they mean.
If you are having problems with your furnace, let us know. We can come out and take a look at your heating system, let you know what the sounds mean, and recommend a service, repair, or replacement. Give us a call at (276) 690-9222, or click on the button below to contact us online!
What Are Normal Furnace Noises?
Before you start to panic when you hear your furnace making a noise, understand that furnaces aren’t completely silent. Normal furnace noises could be a soft hum from the motor or air movement. You may also hear a faint whoosh when the burners ignite. Depending on where the vents are, you may hear the air coming through them as well.
These sounds should be consistent and not too loud. If you start hearing loud noises, or something outside of this description, we recommend contacting an HVAC contractor, like the pros here at Complete Comfort.
12 Common Furnace Noises and What They Mean
The sounds your furnace makes can be a good indicator of its condition. Not all of them are a bad sign, and depending on the sound, we will try and explain what it means.
Here’s a list of 12 common furnace noises and what they potentially mean:
Rumbling
A rumbling noise when the furnace runs or shuts off could be an indication that the burner is dirty or that the pilot light is improperly adjusted. This can lead to inefficient furnace operation, and a regular furnace service will be able to clear this up.
Screeching
Screeching sounds often suggest a problem with the blower motor or the inducer motor. It may be that a bearing needs lubrication or that a belt is worn out and needs replacing.
Vibrating
Vibrating or shaking sounds could point to a loose panel or a screw that needs tightening. It could also mean that the blower wheel is unbalanced. This is another problem solved with a regular service.
Clicking
While a clicking sound upon startup is normal, if you continue to hear clicking, this could be an issue. It might indicate a defective relay or a problem with the control panel. Call in a pro to take care of this one.
Banging
A banging noise when the furnace makes a popping noise when turning on can be caused by the ductwork expanding and contracting. This is something you shouldn’t worry about.
However, if it’s a loud bang, it might be a small explosion within the furnace, potentially because of a delayed gas ignition. Just like when you let gas build up on a grill, then throw a match in, it causes a big flame to start. If this happens in your furnace, it could cause damage and become a problem.
Humming
A humming sound could signify an issue with the blower fan or capacitor. If the humming is louder than normal, it could suggest the fan is working harder than it should.
Read More: The Furnace Maintenance Checklist
Rattling
Rattling noises are often related to loose components. The panels might need tightening, or there might be loose screws or bearings in the motor. If it’s an outside panel, you may be able to tighten it yourself.
Pops
Pops or pinging sounds often come from thermal expansion—the ductwork is adjusting to the change in temperature. This is a common sound that you shouldn’t be worried about as long as it’s not too loud.
Chirping
Chirping when the furnace starts up is typically normal, as it’s often just the sound of the metal components warming up and expanding.
Buzzing
Buzzing noises could indicate electrical issues. This sound should not be ignored, as it could relate to something as serious as a failing motor.
Knocking
Knocking sounds can be caused by the blower assembly. If something is obstructing the blower or if it’s misaligned, it might create a knocking sound.
Scraping
A furnace grinding noise, especially one that resembles metal hitting metal, suggests that something is seriously wrong. This could be a sign that the blower wheel is loose and scraping against the blower casing. Call your HVAC contractor right away!
If you live in the Chilhowie, VA area, give us a call at (276) 690-9222, or click here to visit us online!
FAQs
When it comes to furnace maintenance and noises, homeowners often have a few common questions:
Should you be able to hear your furnace?
Yes, you should be able to hear your furnace operating, but the sounds should not be disruptive. You should hear it kicking on, and a low hum when it is running.
Why is my heater making a weird sound?
Heaters can make weird sounds for a multitude of reasons, such as dirty burners, loose parts, or airflow disruptions. Give your HVAC contractor a call if you want an expert opinion!
Why does my furnace sound like a freight train?
If your furnace is making a loud noise like a freight train, it could be an issue with the blower motor. If the motor is operating at a high capacity or there are other mechanical issues, it can produce very loud noises. A blocked air filter causing the motor to work harder could also be the culprit.