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Serving the Southern California Area



Serving the Southern California Area


Smart Choice Heating and Air Blog

Sounds You Should Never Hear from Your Furnace


We seem to be just about winding down on our furnace use. Though, as we all know, we can still be in for a cold spell in the coming weeks, and you never know if you might need your furnace for one last show. Whether you’ve already shut it down for the season or expect to turn it back on again, one thing is for sure. If it was making any unfamiliar noises, you need to have it checked out by an experienced professional!

There are certain noises that simply shouldn’t be ignored, and letting a furnace sit in wait until next fall can be detrimental to not only the heating system, but your air conditioner too—which shares components like ductwork and the thermostat. If you are hearing any of the following suspicious sounds, please don’t hesitate to schedule an inspection with one of our technicians.


A loud screeching noise is most likely a sign that the blower motor in the furnace isn’t working as it should. A malfunctioning blower motor means that the heat produced by your furnace won’t be able to circulate warm air around the home successfully.

This may just mean that the blower motor is in desperate need of lubrication, which is an easy fix for our technicians to make. Another possibility, however, is that the fan has stopped. Of course, to accurately diagnose this scenario, it’s important to call in a trained and experienced HVAC technician.


Do you hear something that resembles metal on metal? Then you probably are hearing metal on metal. And this can be a sign of a serious problem with the furnace’s blower wheel. If this is the case, you need to turn off your furnace and contact a professional right away in order to prevent further damage to the wheel. More damage to the wheel means more damage to your wallet!

Banging or Booming

Typically, the bang or boom you may hear coming from your furnace is indicative of a dirty burner, which can be quite dangerous. The noise you’re hearing is caused by a delay in ignition due to dirt or grime buildup. The gas then builds up too, and when it ignites, a small explosion occurs inside your furnace, which rattles and can eventually crack the heat exchanger.

Cleaning the burners yourself is not recommended. There is no room for error, and the last thing you need to do is spend more money than you should have to. It’s always a safer and more economically beneficial decision to call in a pro for this kind of work.


Rattling doesn’t really seem like a threatening noise, right? It might not be a big deal, but you should never just assume it’s something minor like a loose panel or screw. A broken heat exchanger could be the cause of the rattle, for instance. A cracked heat exchanger will lead to carbon monoxide leakage, which is a harmful gas that can threaten the health and safety of your family.

For professional furnace services in Anaheim, contact Smart Choice Heating and Air—Dedicated to Great Service, Clean Air & Happy Homes!

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