Check the stove fire cement

Fire cement is used to seal joints between stove components, particularly around the flue collar, door frames on some older stoves, and anywhere two cast sections meet. It's a sacrificial sealant that cracks and crumbles over time with the thermal cycling. That's not a failure, it's just what fire cement does.

Check around the flue collar where the pipe meets the stove, and around any cast iron panel joints. Small cracks are normal. What you're looking for is gaps where smoke or flue gases could escape into the room, or sections that have completely fallen out. Run your fingers along the joints when the stove is cold, and look for daylight or drafts.

Repointing is a simple job. Rake out the old loose material, clean the joint out with a brush, dampen slightly, and press new fire cement in firmly with a small tool or your finger. Smooth it off and leave it to skin over before lighting. Most fire cements need a slow curing fire before they harden properly, so don't build a big fire on the first use.