I've been tweeking my new EKO 25 for the last two months and have received a pretty good education. In my "new" retirement home (960 sq. ft. 1970's ranch) about one heating season of oil heat sent me boiler shopping. My first issue with the EKO was creosote in the flue pipe. At idle my chimney would smoke like a choked down fire in a woodstove. I found that the inlet flap was not closing. Several issues were at work causing this problem. The panel was "oil canning" when the screws were tightened so I installed a couple screws to act as standoffs to keep the panel flat. That was an improvement but did not completely cure the problem. I then glued a couple washers (weight: about 50 grains measured on my bullet scale) to the counterbalance. That was a huge improvement. I also observed that someone, apparently in the manufacturing of the unit had trouble with the screws on the panel and it did not seat well on the gasket. Temporarily applied some modeling clay to the joint which also improved the situation Unit is in my basement and only have 105 gallons of storage. This needs to change. Going to try to build my own tank. Seem to have overcome the creosote smell emitted by the unit that seems to be plagueing many EKO owners, not by playing with the door gaskets but by sealing every connection, slip joint and seam in my flue pipe. More on my adventures later.