Hi Ronlary,
I'm not sure if I can follow your water heater's vent connector as far as up and down sections go, however, when you look at the entire assembly, there should be no part of it between the WH draft hood, furnace connector joint, and the chimney flue that has a negative slope.
There must be at least(!) a 1/4" rise per each linear foot of the run towards the chimney, the vent connector can never run down.
Let me know if you have more questions, just click "comment" below.