I have an AHS E140 Wood Gun system for sale. I purchased in 2008 and have used every winter since 2009. Age and circumstances in life have brought about the decision to quit wood burning. The system includes a 300 gallon storage tank and an Amtrol expansion tank. I'm pretty sure the center bricks are the 2nd set I've purchased from AHS, and will probably need to be replaced after this winter. I've looked into making my own, but with selling in the back of my mind, I've held off. The unit is a carbon steel model. I chose carbon steel after a couple discussions with an engineer at AHS, which resulted in the CS model decision. I fire the boiler once a day and run hot until full temp is reached, then shut down. Those that choose to pack the boiler and let it cycle are better off with a SS model. The storage tank is a heavy wall propane tank with an insulated cover. I put R19 fiberglass insulation around the tank, then covered with a fiber-woven material to keep inplace. I wasn't sure if I wanted to spray foam, and thought I'd try the insulated cover. It's worked great for 15 years. I'm asking $4500 for all.