I have a 30 gall. water heater in a closet that sits underneath the a/c.(first floor condo) I need to run a 3/4" drain line somewhere. There is a Drain standpipe in the wall that the a/c condensate is tied in to. Can I tie my drain pan line into this same standpipe? If so, what kind of a fitting could I use to tap into the standpipe without cutting it and using a union?(maybe a saddle type connection?) Also would there need to be a check valve or something in the line in case this condensate line backed up?
This closet is on an outside wall. Would it be easier to just poke outside the wall with a piece of pipe?