So the owner and installer are coming at 10am tomorrow. I will have them remove the mesh. I have the one inch screen you are talking about. I used it when building the chicken coop and I have wire cutters. So once I see what they removed I'll be able to tell you if this was the cause. I'll ask if they can put the 1 inch mesh up. The chap came after hours after he had finished his regular work. It was dark. It seemed like they felt they were doing me a favor. We don't have a lot of options way up here. I feel like they should leave some space in their schedules for emergencies but I don't know how the industry works. If that's too much to ask. I have always been able to clean and inspect my own chimney from my own roof. This is first house where I just can't go up that high and the pitch is very steep. I wonder if I can undo the pipe in the attic and clean from the attic up and from the attic down. I hate relying on folks. We will have been without heat in most of the house for almost a week. I'm a DIY nut so this has been hard on me.