What's In Your Furnace? Why You Should Probably Take A Look

Furnaces can get dirty, just like anything else in your home. Sometimes, furnaces can get very dirty with objects you would never have expected. If you have never looked inside your furnace ever, or this is the first chance you have had to look, you should definitely watch as the HVAC technician cleans out the furnace. To prepare yourself ahead of time, the following things are just a sampling of what might be in there.


Spiders crawl into everything. They do not have the capacity to discern that something is not habitable just because it exists. There may be living spiders in the furnace as well as past shells and corpses of spiders that went in there months ago. The technician may jump or may not; either way he/she will clear these creatures out and destroy them if they are still living. 


Along with the spiders come cobwebs. Cobwebs are leftover remains of webs and travel threads used by spiders to move about inside this space. Since spiders do not gather up the silk threads they use after they have spun them, these threads have been left to collect dust inside the furnace. More dust collects into dust bunnies around the cobwebs, leaving behind a lot of dust to clear from this appliance.

​Dead Insect Carapaces

Any insect that crawled into the furnace and met its fate against the spiders or when encountering the extreme heat of flames leaves behind its ​carapace​, or the exoskeleton of its body. You may see more than one of these insect corpses in the dust and dirt inside the furnace. When the technician vacuums out the dust, spiders, and cobwebs, he/she will be sure to vacuum out these dead insects too.


This is rare, but it is not entirely unheard of. Mice may find their way into your air ducts and rummage about because this is where it is the warmest for them. Their lifespan is short, and even shorter if they consume poison and die in the air ducts. If a mouse makes it to the furnace before dying, it may still be present in the form of a rotted out corpse, fur bits, and/or bones. There may be other signs that there were mice present, such as feces and tracks through the dust. Whatever remains, it will be cleaned out with the rest of the various bits of debris.

Contact a service like Always Ready Repair for more help.