WH & furnace T connection

Ranch style townhouse. Natural draft WH in utility closet on 1st floor. 80% induced draft furnace in attic. WH flue Ts into furnace flue in attic. Usually not concerned with this but because the WH is natural draft should this connection be a Wye connection?

I could be wrong, but I seem to remember reading somewhere that a natural draft should not be attached to an induced draft/ powervent system. I don’t recall ever seeing that setup, thus my not being sure.

Thanks, Jeff, yes, that is why I am questioning this setup. Natural draft and induced draft in using same flue. With the WH on the 1st floor and the furnace in the attic, how much will the WH draft be effected though?