Hear Strange Noises From Your Furnace? It May Be Heading for an Expensive Breakdown
The Furnace That Runs Too Loudly: Noise is the last thing you want from your furnace, especially at night when you’re trying to sleep. But strange noises can be more than a nuisance; they could signal that a small problem is on the road to becoming a big and expensive breakdown.
Let’s take a look at some of the sounds you might hear, why you should never ignore them, and what to do about them.
Why Furnaces Should Run Quietly
While some components may make a little noise when starting up or shutting down (think soft humming or clicking), modern furnaces are generally quiet. Loud bangs, rattles, squeals, thumps, and any other loud, unusual sounds are not normal and require investigation by an HVAC professional. A furnace that suddenly starts to sound like a whole different machine can be a clue that internal problems are developing.
Strange Furnace Noises and What They Mean
1. Banging or Loud Thuds on Startup
A loud bang when the furnace first turns on may indicate ignition issues or gas build-up before combustion. The problem can stress internal parts over time and lead to damage to the heat exchanger, gas valve, or other components.
2. Rattling or Clanking While Running
Metal parts hitting each other due to loose screws, panels, or internal components can create rattling or clanking noises. While it may not be an emergency if you hear this, it is not normal and can lead to deeper mechanical problems or be an early warning of a cracked heat exchanger, which is a major safety issue.
3. Squealing or Squeaking
Metal grinding against metal or other friction is often caused by blower fan or motor problems. Worn or loose belts, deteriorating bearings, and other parts may squeal or squeak if not lubricated or replaced by a technician. This will shorten the life of furnace components.
4. Buzzing or Humming Louder Than Normal
Buzzing transformers or capacitors can happen when parts become loose, or other electrical components are strained or failing. Some humming may be normal on a very quiet system, but buzzing is more often a sign of worn parts that need to be diagnosed by a professional.
5. Whistling or Whooshing Sounds
Any air moving through a constricted space can whistle if there are airflow restrictions on your furnace.
Why You Shouldn’t Ignore Strange Furnace Noises
A loud furnace isn’t always the sign of an emergency or imminent breakdown, but it’s almost always an indication that something is wrong. What may start as a small problem or nuisance can quickly lead to:
• Decreased efficiency and higher heating bills
• Lost heating capacity when you need it most
• Accelerated equipment failure and costly repairs
• Safety hazards such as cracked heat exchangers and carbon monoxide leaks
Furnace problems at night can be especially inconvenient and uncomfortable in Arlington Heights, Evanston, Des Plaines, Highland Park, and other Northwest Chicagoland communities when the temperature dips below freezing and snow is falling.
What to Do When Strange Noises Start
A few furnace noises may be fixed by checking or adjusting the most basic components. Before calling for professional service, check:
• Replace a clogged air filter
• Ensure that vents are not blocked
• Tighten any loose screws or panels that are easily accessible (only when the system is off and completely cooled down)
But if strange noises continue, contact an HVAC professional to diagnose the problem. You shouldn’t keep running a furnace that makes strange noises or keeps shutting down.
At Home Comfort, our technicians are available seven days a week in Northwest Chicagoland to inspect, diagnose, and repair furnace problems before they become major and expensive repairs. Contact us today to get peace of mind that your heating system is safe and operating efficiently.
Frequently Asked Questions About Strange Furnace Noises
What causes strange noises in a furnace?
Strange noises are usually caused by loose components, ignition issues, airflow restrictions, or worn mechanical and electrical parts.
Are strange furnace noises dangerous?
Some noises can indicate safety risks, especially if they involve ignition problems or overheating components. It is best to have the system inspected promptly.
Can a furnace break down if it is making noise?
Yes. Strange noises often appear before major failures. Ignoring them increases the risk of a complete breakdown.
Why does my furnace sound louder at night?
Longer run times and colder temperatures at night increase system stress, making existing problems more noticeable.
Should I turn off my furnace if it makes strange noises?
If the noise is loud, sudden, or accompanied by loss of heat, turning the system off and calling a professional is recommended.
Community Served
In Park Ridge, Skokie, Morton Grove, Oak Park, Palatine, and the many other communities we serve across Northwest Chicagoland, we’re always here to make sure your home stays warm and cozy this winter and in years to come. We don’t let strange noises at night keep us from providing fast, friendly, high-quality service for our neighbors.
