Help With Making Buck 91 Work Correctly

[Poseidon215]

So years ago my parents purchased a buck 91 and decided to install it themselves. I was helping get them ready for the upcoming winter and noticed quite a few things I didn't think were quite right.

They have an 8" flexible stainless liner that extends all the way to top of 25' chimney. There is no block off plate or any kind of insulation at the top or bottom. My guess is there is a lot of lost heat happening and the abundance of creosote buildup each year is from the gases cooling on their way up. The cap on pipe just has a cage around it to keep anything from getting in and it was probably 50% blocked with creosote. There is just a piece of sheet metal covering the old tile 14"x14" opening

Also they have been having problems since day one getting an overnight burn. The box can be hot loaded around 1000 degrees and packed full but after 4-6 hours it's around 400 degrees and barely any coals. I tried shutting it down more with just the air wash opened enough to keep a very slight flame going. Not sure how people are getting 12 hour burn times with any kind of heat production. There's gotta be something else going on or just a big oversight in operation. I'm open to suggestions.

 

[mellow]

Dry wood is the key to long burns, you want a small flame and as little air as possible for 8+ hour burns and dry wood is the only way to accomplish this. Otherwise you burn up all your wood getting the cat probe up to operating temperature and then you have to do more air which burns it hotter.