Hey guys, saw holes drilled in a return ( about 50 of them ) right at the unit in a basement, code I believe says you cant have any openings in a return within ten foot of the unit as it can pull combustion gases into the dwelling, is that true with a enclosed chamber that draws combustion air from the outside ? I wrote it up and the answer was to draw moisture out of the basement. I also wrote it up as the ducts may not have been figured correctly and they needed more warm air for the air handler. What are your thoughts thank you. Also what is the pitch on a gas water heater exhaust.