30/08/2025
If your flue has a rust spot on the outside like this one it means it has had a chimney fire in it at some stage. The heat causes the gal coating to let go and rust sets in. Rust around the top hat like this one will also let water in to the inner flue when it rains. Make sure your flue is cleaned from the top if possible, not just a quick scrub from the bottom. All these repairs would have been missed if only checked from the bottom.