Replacing PV water heater with DV water heater?

[Walshkeys]

I have a 20 year old POWER VENT water heater that’s finally dying. Small leak creating a little pool in the corner of my basement.
I’m looking at Rheem heaters at Home Depot and I see some direct vent water heaters for a decent price at 12 year warranty with WiFi enabled maintenance.
The power vent models are only 6 year warranty, no bells or whistles, and far more expensive.
Can I pop in a DIRECT VENT water heater utilizing the vent piping already in place? Or do I need to install all new venting? Does Direct vent need to be completely vertical? Here are some photos of my current system. Thanks!

 

[Mr_David]

You have to use a power vent that allows you to use the same vent material.
Direct vent is a beast all on it's own.

A direct vent refers to a heater that has a dual vent system.
It draws all combustion air from outside.
They have direct vent power vents that use 2 vent.
But the Direct vent non-power type uses a special 2 way vent.
The outer shell is for combustion air going into the heater and the inner tube is for burned exhaust.
Those vents terminate just outside the adjacent wall and don't require them to terminated above the roof.

You maybe be asking if you can use a traditional type water heater which uses a GRAVITY / CHIMMINEY vent.
NO!! You CANNOT use a gravity vented water heater with a plastic vent.

You better read the instruction for the replacement and understand them before you try to replace it yourself.
I see DIY'er WH installs often. Although they work, are often installed incorrectly and not to code.