When any appliance makes loud noises, it is usually not a good sign. If your furnace is making a loud sound, it means that something is wrong. However, the tricky part is figuring out what part isn’t functioning properly. Calling in a service technician is a quick way of figuring it out, but knowing what your furnace noises likely mean can point them in the right direction.
When your furnace kicks on, if you hear a loud screeching or rattling noise then it means it is probably time to lubricate the bearings on your blower motor. As the major moving part that forces warm air into your home, it needs frequent lubrication.
If you begin to hear the sound of metal scraping on metal, this is one of the most serious sounds you can hear, and it is probably your blower wheel. When metal scraps on metal, it wears everything down quickly. The fan has most likely become loose and it bouncing around in the housing. Turn off your furnace so no further damage is done.
Does your furnace make a boom when you turn it on? It’s kind of scary, and you should be concerned about it. That “boom” is essentially the gas building up and then suddenly exploding. In many cases, the burners need cleaning. When the burners are soiled, they can delay the ignition and cause that terrifying noise.
The vibration from the furnace has a way of loosening screws sometimes. If you hear a slight rattling noise, the most likely culprit is a loose screw somewhere that needs tightening. However, this noise shouldn’t be ignored.