OK, boys and girls,here we go. I need all the help I can get on this one. As you look at the picture you will see two gas hot water heaters combined to go out the ceiling throught one single lining flue. Also, there is a flue from the direct vent fireplace with zero clearance to the ceiling board and the back of the fireplace is directly against the hotwater heater.
What you don’t see is the “t” for the TPR valves, and the flex pipe going directly into the housing for the gas fireplace.
Give me code and comments, PLEASE!!