Lined chimney for atmospheric water heater vent?

[Tim Moyer]

We have a 2017 Bradford White atmospheric vent gas water heater. It is vented to a lined chimney (lined for the water heater) and the only appliance that uses the chimney. I'm trying to read the 2024 IRC chapter 24 for the rules on venting this type of appliance. My neighbor was told that gas water heaters (atmospheric vent) could no longer be vented through the chimney, but I can't find this in the codes.
When our current gas water heater needs to be replaced, do I need to vent it differently?

 

[Fitter30]

Biden signed into law that by 2029 all gas heaters will be condensing type.
Trump has rescinded that rule. Standard flues will still be used. They make a flue liner for condensing furnaces and water heaters.

 

[Sponsor]

 

[Tim Moyer]

Thank you.
I'll add it to the "flip flop" list.