Removing wasp nest in outside air kit intake

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New Member
Oct 21, 2023
We have a Hearth & Home GR18 wood burning fireplace insert on the side of our house, built in 2014. It sits inside an exterior wood chimney chase, and has the outside air kit vents on the side of the chimney. We discovered paper wasps built a big hive in the intake vent, and were making their way into the house through the edges of the fire box. The exterminator killed the hive by injecting poison into it through the vent opening, but suggested we remove the hive before using the fireplace again.

Has anyone had anything similar happen? Do I have any options here other than removing the chase siding and removing the air kit to make sure the hive doesn't extend into the fireplace insert itself? If the hive does extend into the fireplace, is it safe to use? I assume the hive will burn off, but if inside the metal of the fireplace that's not a hazard?

I'm a total novice when it comes to this (construction, fireplaces, and wasp removal) so I'm not going to be offended if you tell me I have this all wrong.
The nest was likely just at the outside entrance. Preliminary cleaning can be done with a dryer vent cleaning tool. If there is no resistance or debris after the first foot or two, then the fireplace is likely ok and nest free. Vacuum out all debris before starting the fireplace. A boroscope or sweep camera could verify that the outside air duct is nest-free.
Depending on the species of wasp, they may build out the entire hose. I’d pull the hose and make sure it’s clear.
If it's paper wasps they don't store honey for the winter so the nests are generally smaller. If however, it is another species then the nest could be deeper in the pipe. A camera can verify the extent of the nest once the initial mass is removed. If the nest is deep in the duct I agree that the best course of action is to create a service door on the outside of the chase and remove the outside air line to clean and inspect.
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