After 3 months, my side firebrick was buldging out. I removed the four worst ones, and the more intense heat melted a 1/2 inch wall of creosote away. I was then able to scrape it clean and fully insert the brick back in. Thus, I think the creosote coming down the wall sides is working its way behind the brick. I plan to try keeping the brick in for the time being. I have been fairly satisfied with the 2300 so far, but there are many design changes which really should have been made first. I agree that this unit looks rushed to market and I bought a CB because I was expecting better. I did pay top dollar and I am a bit disappointed. Here is a list of design issues I encountered: 1) Box fire brick buldging 2) Heavy firebox creosote seems part of the design, although it burns clean 3) Leak in flange above pump wrecks pump (water drips right into pump electronics). 4) Insulation in back of unit is user installed, yet critical to be done right to prevent freezing or over-insulating pump motor 5) Areas (crevases) in firebox difficult to clean 6) No included alarm system to detect power failure, pump failure, or low fire which could result in poor operating or frozen system 7) Damper door difficult to open 8) Light above door gets smoke covered quickly 9) Need to stir bottom coals and ashes to prevent air holes from plugging 10) Damper only slightly prevents fire from rolling out the front door 11) Reactor chamber bricks came loose. 12) Reaction chamber door and cover design is awkward (removing cover, where to put while cleaning, etc) 13) Color of unit helps it look rather ugly as it gets "dirty" 14) Better insulated thermopex with real specification on how much energy is lost 15) Better integration with existing boilers - mine has been poor, Pumps need to be matched, prevent boiler from firing, etc. 16) Better sealing adjustment system on door. 17) Less power consumption of fan - mine runs on "low" always, but the design simply partially "plugs" the fan opening which I bet is not the best design.