Or, the HVAC installers never read the manuals. Devils advocate.
I honestly don’t disagree with this statement. I could always use more knowledge, hence this conversation.
I agree, but in my opinion it depends on where the connection is. In my photo, I do not believe that natural draft WH will properly vent it’s exhaust with two fan assisted appliances running in congruent with the WH when the WH is the first in line. Maybe if the WH terminated AFTER the two T’s I would hold a different opinion but that is not the case.
I read all MFG manuals to determine whether or not the flues can be commoned or not. The flue itself might have a different recommendation on the installation but I follow what the MFG manuals say for furnaces, boilers and WH’s.
This may be true, but the appliances may not allow this. This is why I read what they recommend.
This in someway is along the lines of what I am getting at, which again, is why I read all the manuals to determine how it should be installed.
I can sense the sarcasm. No reason to be mad.