Why Is My Furnace Rattling? Expert Tips And Tricks

If your furnace is making strange noises, it could be a cause for concern. Rattles or bangs could mean loose parts, while clicks and thwaps may indicate ignition system issues. 

In this blog post, we will study in detail the reason behind the rattling sound made by the furnace.

Why Is My Furnace Rattling?

Why Is My Furnace Rattling

The rattling of the furnace may be produced due to the squealing or thwapping of the motor which makes weird sounds indicating that the furnace needs to be fixed.

Common Reasons for Furnace Rattling

If you hear rattling sounds from the furnace, it may be due to the blower wheel or metal ductwork. 

Squealing and wapping can indicate a problem with the blower motor or access hatch.

Rattling sounds from your furnace is not something to ignore. Common causes include,

  • Loose parts requiring tightening or replacing
  • Blower wheel
  • Motor or ignition system issues may also require professional help
  • Delayed ignition can cause banging noises

Cause of Furnace Sounds

Furnace sounds can be nerve-wracking. Understanding the cause might help you resolve it quickly. 

  • Check for loose bolts or ductwork that moved out of place.
  • Ignition systems or flame sensors could be to blame. 
  • Scraping, blower wheel or motor, thwapping, blower needs oiling.
  • Dangerous issues like carbon monoxide poisoning or delayed ignition, leading to cracks in heat exchangers, could be caused by strange furnace noises

It’s important to get a professional HVAC technician to inspect and identify the root cause of the noise before serious damage.

Signs of Potential Carbon Monoxide Poisoning

Carbon monoxide poisoning is a life-threatening issue that can occur in homes with gas furnaces. 

This silent killer can be devastating if undetected. To detect potential poisoning, watch out for signs like:

  • Headaches and dizziness
  • Nausea and vomiting
  • Shortness of breath and confusion

Carbon monoxide poisoning can be caused by problems with the furnace’s ignition system, delayed ignition, or a cracked heat exchanger.

Also, remember that a clogged or dirty air filter can restrict the flow of air through the furnace and cause carbon monoxide buildup.

Tips for Furnace Maintenance

Maintaining a furnace is key for winter comfort. Annual maintenance checks and air filter replacements can help prevent problems with the blower wheel, motor, and ignition system. 

If you hear noises like rattling, popping, or thwapping, it may indicate an issue with the burners, parts, or ductwork. 

  • Clicking or scraping sounds could mean carbon monoxide poisoning, so call a furnace technician right away
  • When maintaining your furnace, check the belts for damage and replace them if needed
  • Loose bolts and leaky ducts can cause banging when the furnace starts. 
  • Inspect the access hatch and burner when scheduling an annual maintenance appointment with a technician. 
  • Clean the metal panels to increase efficiency and avoid future damage.

Aftercare for Furnace Noises

These noises may also be due to a dirty air filter, loose bolts, or damaged ductwork. Ignoring them could lead to further damage to your HVAC system.

To take care of furnace noises, call a professional technician. They will inspect the various components of your heating system and fix any issues. 

Never ignore popping or rumbling noises, they may be due to delayed ignition or carbon monoxide poisoning, which can harm your family and pets.

New systems need even more care than old furnaces. If the blower motor or wheel is making squealing noises, it could require extra attention even if the rest of the unit seems okay.


When buying a new heating system, get a high-efficiency one to save money. A professional can help you find an affordable system that provides the most comfort.