Winter Pest Problems

Winter Pest Problems That Could Be Affecting Your Heating System

As the days grow colder, a group of new guests may be interested in calling your house home: These pests from outside can cause damage, especially to the heating system you’re using to keep your home warm. This can be all too common during winter months!

If you notice signs that you are having pest issues, it may be time to call pest control – and consider contacting American Comfort Experts if it looks like they caused a problem with your heating, too. Take measures to prevent pests from entering your home in winter, and you can put a stop to problems like these.

Rodents in Ductwork

Ducts carry air throughout the house after it has been heated and are a very important part of an HVAC system. However, over time ductwork can develop cracks, or pests can find sneaky ways inside – especially inquisitive rodents. Once inside ductwork, rodents quickly set up shop: They have found a dark, safe place that’s regularly treated to warm air, so from their perspective it looks like paradise. This is how rats, squirrels, mice and other rodents build their nests inside ductwork, and it’s a problem we see frequently.

Not only are these nests unpleasant, but they can also inhibit airflow and keep the HVAC system from doing its job, while also letting cold air into the ducts if enough material has been chewed away. Speaking of chewing, rodents may also get easy access to electrical wiring from these locations, and no one wants rats chewing on their wires! This can cause electrical fire dangers and end up killing rats, so they decompose inside your vents where you really don’t want them.

The best way to prevent these problems is to make sure your ductwork is properly installed and sealed, and that any cracks or gaps are quickly repaired. Duct cleaning can help fix any current issues.

Insects in Vents

Rodents aren’t the only ones that can cause problems with vents and ductwork. A variety of insects and spiders also like to seek out vent systems for their warmth. The good news is that these insects don’t do much physical damage to ductwork. However, homeowners sometimes make the mistake of trying to treat these infestations by spraying pesticides down their vents. Unfortunately, this is a big mistake that will end up blowing toxic chemicals around your home for the rest of winter and may require duct cleaning to fully remove. Instead, look for screens that you can install over vents and other measures to keep the bugs out in the first place!

Raccoons in the Attic

Warm air rises, and that means that a lot of the heated air in a home will eventually end up in an attic or upper crawlspace. This is very attractive to animals looking for a warmer space to sleep during winter, and raccoons are one of the worst culprits for these problems. They can do significant damage to your insulation and cause other issues if they decide to make your attic a home. Upper insulation in a house is very important (as is proper venting) to keep houses warm in winter, and you really don’t want any animals messing with it.

If you need to replace insulation near your roof after a pest problem, it may be a good idea to consult an HVAC company or roofing expert to ask about venting. If you close off all venting during the winter, this can cause serious condensation problems inside attic areas, so some access to outside air is always necessary. Just make sure that access isn’t enough to allow raccoon inside!

Bugs in Heating Units

Many bugs also seek a warm shelter for winter, including stinkbugs, silverfish, cockroaches, and other annoying species. These bugs often go straight for heating units like furnaces and water heaters. When this happens, it can quickly become a problem: These units depend on sensors and advanced electronics to do their jobs effectively. Bugs can damage more delicate systems inside heating units and keep them from working properly, so they require diagnostics and repairs. Avoid this by making sure your home is well sealed for winter weather.

Squirrels in Your Chimney and Roof Vents

Chimneys and other heating-related roof vents can look very attractive to squirrels looking for a warm place to nest (bird nests are also an issue, but less common in winter). Unfortunately, this also blocks these important vents and can create fire hazards, smoke issues, or reroute fumes back into the house. Make sure your chimney is clean when starting your winter heating and install guards or caps to prevent nesting issues.


Snakes are a bit less likely to enter your house during winter or cause a disturbance, but they do seek out warm spots for hibernation…which can lead them to coil up in the condenser. Unless you have a heat pump your outdoor condenser isn’t likely to see much use in winter – but you turn it back on for summer, you may find you are cutting up a bunch of snakes with the fan mechanism! This can be very damaging for the AC unit – and, of course, for the snakes. Clean out your condenser before you use it again in the spring.



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