Buddy of mine had the same thing happen last winter over in Irondequoit. He went up there thinking it was a quick brush job and next thing he knows the whole liner is sitting in the driveway in a big coil. Turns out the thing was so rusted out it was basically held together by the nest itself. He ended up telling the homeowner it was either replace the liner or risk carbon monoxide backing up into the house, which is not a fun talk to have in December. Cost him way more time than the job was ever gonna pay for.