Our homes’ furnaces help keep the interior of your home warm and cozy no matter what the weather’s doing outside. Unfortunately, a furnace is an appliance, and all appliances break down after a time. It’s best to know before your furnace is on its last legs before it conks out, so you can make the necessary moves and not be left in the cold when your furnace fails in the middle of the night.

Luckily your furnace is very vocal and will often express when it’s not feeling so good. Here are the three most common sounds that signal furnace failure or the initial stages of failure.

Three Sounds that Signal Furnace Failure


Scraping indicates that metal is rubbing on metal which is never good for a furnace. Metal to metal contact indicates a part or component has come loose or something foreign has become trapped in your furnace. Do not attempt the investigate the scraping sound yourself, let a professional HVAC find the problem.

Banging (Thumping)

If you hear banging, sorry Charlie, your furnace may be on its last legs. While scraping and popping may indicate fixable problems a banging sound means that your furnace is struggling to do its job and could be on its last legs. Banging or thumping means that your furnace is begging for help. Give it the help it needs by calling your local HVAC service. They can let you know if the problem is manageable or if it’s time to consider replacing your furnace.


Popping is another indication that your furnace is working too hard but doesn’t usually carry the same negative diagnosis as banging. Popping could indicate dirty burners, that your filters need to be replaced, or that your furnace is becoming inefficient. If you hear regular popping let an HVAC tech examine your furnace.

There are many things that go bump in the night, but you don’t want them to be your furnace. If you hear banging, scraping, popping, or humming, it’s time to call your local and reputable HVAC technician to look over your system. A reputable HVAC can help determine what’s causing the noises, what can be done if anything to fix them, and if your furnace is on its way out. If your furnace has a lot to say – call the pros.