Serious question, had a flue tile crack on a job in Boise yesterday and had to improvise a temporary seal with high-temp mortar and a steel band.

The homeowner's old furnace back-puffed during a test fire, and the sudden pressure shift split a tile three feet up, so I mixed a fast-set mortar, wrapped the section with a band clamp from my truck, and told them to keep it under 300 degrees until I can replace the liner next Tuesday.

3 comments

3 Comments

andrew9161d agoMost Upvoted

Honestly, telling them to run it at all makes me nervous. I mean, that back-puff already showed a pressure problem, and a band-aid fix doesn't solve the root cause. I'd have shut it down and told them no heat until the new liner is in, even if it means getting them some space heaters. The risk of CO or another crack just seems too high to me.

elliotl244d ago

That's a solid field fix for a sudden crack. I've used muffler band clamps with furnace cement as a temporary patch before, and it held for a week without issue. Just keep an eye on it until the proper liner goes in.

grantthomas3d ago

Good call on the temp fix, that's exactly how you stop a small crack from becoming a full liner failure. Just make sure the homeowner knows not to run it hard, because that mortar can only take so much thermal cycling before it gives out. Honestly, telling them a firm temperature limit was the smart move. You see a lot of guys just patch it and walk away without that talk. Next Tuesday isn't far off, so the risk is pretty low if they listen.