Your furnace should be heard, not noticed. A low hum or whoosh of air is normal—but banging, rattling, or squealing? Not so much. Strange furnace noises are one of the earliest signs something might be wrong, and catching the cause early can prevent costly breakdowns.
At Affordable Comfort, we believe the more you know about your system, the better. Here’s a breakdown of common furnace noises, what they typically mean, and when you should call a professional.
Furnace is making Banging or Booming Sounds
What it could mean:
- Delayed ignition: gas builds up before igniting, causing a small explosion.
- Expanding and contracting ductwork.
What to do:
- If the sound happens right as the furnace starts, call a technician. Delayed ignition is a safety issue.
- If the sound is more consistent throughout the cycle, you may just need ductwork adjustments or insulation.
Furnace is Rattling
What it could mean:
- Loose panel or screw.
- Blower motor or fan issue.
- Cracked heat exchanger (serious).
What to do:
- Tighten loose panels if you can identify the source.
- If the rattling continues, shut off the system and call for service to prevent damage.
Furnace is Squealing or Screeching
What it could mean:
- Worn or slipping blower belt (older models).
- Malfunctioning blower motor or bearings.
What to do:
- This usually needs a technician. If it’s a belt, it may just need tightening or replacement. Motor issues may require repair or replacement.
Furnace is Clicking
What it could mean:
- Normal sounds as relays and igniters engage.
- Repeated clicking could point to ignition problems.
What to do:
- Clicking before startup is fine. If it keeps clicking and the furnace doesn’t light, you may have a faulty ignitor or flame sensor.
Furnace is Whistling
What it could mean:
- Airflow restrictions from dirty filters or closed vents.
- Duct leaks.
What to do:
- Replace the furnace filter first.
- Ensure all supply and return vents are open.
- If whistling continues, a technician can check for duct leaks or improper sizing.
When to Call a Professional
Some furnace noises are just annoying. Others are signs of serious risk—like gas buildup, motor failure, or cracked heat exchangers. If a sound is loud, persistent, or new, don’t ignore it. Contact us for furnace repair in Collingwood, Wasaga Beach or Barrie.
At Affordable Comfort, our trained technicians are ready to diagnose and fix the problem fast—so you can get back to peace and quiet.
Prevent Furnace Noise with Regular Maintenance
Most noise problems can be prevented with routine inspections. During a furnace tune-up, our techs will:
- Inspect and tighten loose components
- Lubricate moving parts
- Check gas pressure and ignition systems
- Clean burners and sensors
Strange Noises Coming From Your Furnace? Let us take a listen. Schedule an inspection today and get ahead of a bigger problem.
