Do you have four, six, or eight-legged roommates?
No, not your pets. These critters arenโt so friendly.
Have you ever heard something scurrying in your attic? Or seen something crawling in your unit?
Donโt panic, but your โroommateโ might be damaging your unit.
What Types of Pests Can Invade Your HVAC System?
Bugs (Ants & Spiders)
How can something so small cause so much damage?
Whether itโs an ant infestation chewing on your electrical components or a spider building webs over sensors, these nasty critters can cause a bunch of problems.
Squirrels & Racoons
While they may look cute and cuddly, squirrels and racoons wreak havoc on HVAC units! They have sharp claws and teeth, and they often get trapped in places they donโt belong.
Snakes
You donโt need hands or feet to damage a unit. Snakes will still find their way into your unit, and they can damage your electrical components in the process.
Mice/Rats
Have you ever tasted wiring? We donโt recommend it. For some reason, rats and mice think itโs a gourmet meal! Theyโll gnaw their way right though anything, leaving you with a damaged unit.
What Types of Pests Can Invade Your HVAC System?

Blocked Flue
Unfortunately, birds and squirrels donโt always pick the best places to build their nests. Sometimes, they build in the flue pipe of your heating system. Your flue pipeโs job is to direct deadly gases, such as carbon monoxide, out of your home. If the flue is blocked, the gas canโt get out. It comes back into your home and the air your family breathes.
Everyone knows birds build nests, but did you know squirrels do, too?
Chewed Wires & Damaged Electrical Components
Wires, safeties, flame sensorsโฆ oh my! All of these (and more) look rather tasty to animals like rats and squirrels. Unfortunately, when they chew through wires and other components, it can cause electrical problems in your unit.
Itโs also not uncommon to find snakes caught in HVAC units. Your system gets warm, and snakes love warmth! Theyโll try to slither their way in and around electrical components, but they often end up electrocuted in the process.
Even ants can be a menace when it comes to electrical equipment! Sometimes, ants will chew on your wiring or even carry dirt into your unit.
When critters chew on things in your unit, it can expose wires, leaving your system and home vulnerable to further damage.


Spider Webs Inside Furnace
Nobody likes to think about spiders in their house.
Even if you donโt see spiders in your home, theyโre still bad for your furnace. Your furnace has several types of safety sensors that tell the unit when something has gone wrong. If spiderwebs build-up, the sensors will detect them and eventually shut down your unit because it senses something unusual inside it. Cobwebs, (abandoned and dusty spider webs) can also pose a tricky problem because, as dust collects, they grow bigger and block sensors even more.
Recommended: โ5 Furnace Safety Features You Should Meetโ
Holes in Ductwork
What if you found yourself somewhere strange with no clue how to get out.
Scary, right?
Sometimes, opossums and stray cats find their way into ductwork. When this happens, they might claw or chew through it while trying to escape. Rats and mice cause issues with your ductwork too! They enjoy the insulation itself, and sometimes they chew holes through it. Your ductwork is essential to delivering and removing air throughout your home, so when animals claw through it, that could spell trouble for your HVAC unit.

Prevent the Dangers of Animals in Your Unit and Ductwork with Regular Maintenance
Thereโs no foolproof way to prevent animals from messing with your HVAC system, but with regular maintenance, youโre much more likely to catch these furry (or scaly) visitors before more damage can be done!
Morris-Jenkins offers one-time andย routine HVAC maintenanceย to help your family before these critters cause damage to your unit and your wallet. Want to ensure the best protection? Become aย Priority Advantageยฎ Memberย and weโll check your systems twice a year!
