What you can safely vacuum
We advise that you always allow enough time for all embers to completely cool off and we offer these guidelines to give you a feel for how fire resistant our fabric filters are.
What we refer as a "firefly" is unlikely to burn a hole in our filter. A firefly is like the tiny spark that floats up out of a fireplace, and it glows for no longer than a firefly, about a second, before it burns out.
What we refer to as a "cigarette" could potentially burn a hole in our filter. It is a piece/chunk of partially burned fuel (wood or pellet) that has a red hot glowing ember attached, much like a cigarette. These carry enough fuel with them, that, if lodged against the filter, with swirling air, could heat up and damage the filter.
If you need to clean a pellet stove while the contents in the pot still seem warm, the best way to ensure your AshVac only picks up only ash, and not large hot embers, is to rest the nozzle at an angle directly on the bottom of the pot, and then move it around so it sucks fine ash particles from the bottom of the pile. The narrow opening between the pot floor and nozzle allows ash through, but blocks larger material, including hot embers that are large enough to be problematic.
We do recommend changing the Ash Vacuum filters once a season. They cannot be washed because they have been treated with a Teflon finish. If you wash them they will get sticky. You can clean the filters after each use by removing the rod cover and shaking the shaker basket by grasping the metal rod sticking up out of the lid from side to side. This is just done if you are losing suction but your canister is not full of ash yet.