Beware: Spooky Noises From the Furnace Can Mean a Monster of a Problem
Heaters and furnaces are notorious for making some eerie and mysterious sounds. And they always seem to do it most in the middle of the night, when every little noise seems louder and every shadow seems to hide something sinister. But while some of these sounds are a natural byproduct of the furnace doing its job, others warrant closer attention. Below are a few furnace sounds that can be indicative of major issues in the unit - as if startling the kids, robbing the adults of sleep, and having a generally creepy effect wasn’t bad enough.
Metallic Grinding or Scraping Noises
If the furnace is making a sound like metal grinding or scratching against metal, it’s usually suggestive of a problem with the blower wheel. The blower wheel (or blower fan) draws in cold air via the furnace’s intake vent, pushes it through the heat exchanger, and then forces the freshly heated air out through the home’s air ducts. With such a big task, eventually, the blower wheel and its components can wear down and break.
If even a small mechanical element breaks, the blower fan can become loose and begin scraping against the surrounding surfaces. If this kind of sound is emanating from the furnace, the fan likely needs to be replaced before it can cause further damage.
Banging or Booming Sounds
Loud, sudden bangs, and booms are most often the result of an air duct problem or, in a gas furnace, dirty or grimy burners. In the former case, warm air from a just-engaged furnace is blown into the duct system and causes the cold ductwork to suddenly expand, often with a loud pop or bang. Popping ductwork can also be caused by undersized ductwork or air pressure imbalances.
Banging or booming noises from a gas furnace, especially if they’re coming from the unit itself, are likely being caused by delayed gas combustion due to dirty burners. This means that when the furnace starts up, gas is being pumped into the heat exchanger for a few seconds before being ignited. When the built-up gas finally ignites, it creates a small explosion inside the furnace. This is a serious problem as it can crack the heat exchanger and lead to a gas leak or fire. Fortunately, having the burners professionally cleaned almost always solves the problem.
Screeching or Shrieking
High-pitched shrieking or screeching when the furnace is running (whether it’s electric or gas-powered) can typically be traced to an issue with one or more components of the blower motor. Many of these components require periodic lubrication in order to function properly; if a bearing or drive belt becomes dry, it can produce a horrendous shriek or whine - not to mention be damaged or prematurely worn, in which case it’ll need replacing. Screeching sounds could also be caused by a fault inside the blower motor itself, which usually means the entire motor needs to be replaced.
Though the sounds themselves may range from merely annoying to downright terrifying, and the causes range from minor to seriously scary, there’s no reason to delay getting them checked out. It starts with listening closely, but should always end with the expert diagnosis and service of an HVAC professional.
About LenAire, Inc.
LenAire, Inc. has provided exceptional HVAC services in Bossier City, Louisiana for over 30 years. Their highly-trained technicians arrive on time and ready for anything, with a truck fully equipped with the right parts and tools. Every service is competitively priced and backed by a 100% satisfaction guarantee.
