Why Your Furnace is Making Loud Noises

January 18, 2016

Are the loud noises coming from your furnace keeping you up at night? Furnaces often start to make strange noises when a malfunction is occurring.

Here's what those loud furnace noises often mean:

Repeated clicking noises often indicate that there is a problem with your furnace's ignition system.

Your furnace's spark igniter is trying to ignite your pilot light but is failing to do so resulting in your furnace not starting. If this sounds familiar don't hesitate to give us a call we are open 24/7.

To check whether or not your furnace problems are caused by an ignition switch malfunction you'll want to figure out if your furnace has a pilot light or electric ignition and light the pilot to observe the ignition process to make sure it is functioning normally. Need some help? Contact AJ Perri to give you a hand.

Banging, popping and rattling noises often indicate there is a problem with the blower assembly, motor or furnace burners.

· Rattling can mean a component in the system is coming loose. It's important to repair that component before it breaks or disconnects completely.

· If you hear extremely loud banging sounds shut the heating system off, something most likely has broken and disconnected.

· If you hear a banging noise when the furnace turns on followed by no hot air, dirty furnace burners may be to blame. Dirty furnace burners let gas accumulate in the furnace before the gas ignites. The delayed ignition from the gas buildup is what causes the loud bang. It is important not to ignore this noise. Doing so can crack your furnace's heat exchanger, which oftentimes results in the need for a new furnace.

· If you're hearing a loud noise when your furnace turns on but aren't sure if it's coming from your furnace it could be caused by expanding and contracting air ducts. When your furnace blower starts it sucks in air and blows it out through supply ducts. This causes different parts of your ducts to contract and expand. A minor popping noise is natural, but when there is a loud pop or bang there could be a more serious problem caused by undersized ducts, closed vents or a clogged air filter.

This should help you get a better handle, knowing what's going on with your system and the next steps to take. When in doubt it is best to call a professional to help diagnose your heating system's problem.

AJ Perri is your New Jersey home comfort expert with specialists in heating, air conditioning, air quality and plumbing expertise.

Last Updated: June 09, 2023