I want to thank all the pioneers on this forum. Your collective wisdom has turned my 165 into a efficient system. I upgraded with Shaver Auto Damper Kit with Digital Aquastat & Upgraded Fan from Alternative Heat Supply. Works very well. I am only using one zone so it was a simple thing to drain the tank down to the exit, remove the cap and replace it with a coupler. Installed the dry well, closed it off with silicone, filled it up and fired it up. I also bought two 36" Class A chimneys from Menard's and slid the first one down over the top of the factory chimney and set the second on top and put a clamp on for good measure. I had to remove half of the metal roof to cut it to fit the new chimney and while I had the top opened it allowed me to pull out the old silicone seal from around that fill plate and reseal it much better. I also added more insulation to the top and wrapped my water lines with black foam and then folded bat insulation around the lines and held it in place with bailing twine. So far I am not having the previously constant creosote issues, I am getting consistent temps, set temp at 175 with a 15 degree differential. The temp hits 185-190 before things cool down. The only thing I would like to change is to add a second damper on the chimney. There is a near constant smoke exiting the chimney as the fire smolders. Seems like slowing that down would be a wood saver. Does anyone have any ideas on a second damper install? What is the general opinion of a rain cap/bonnet? I did not buy one, couldn't see the need, but I notice many of the "other" owb do have them.