During the monthly inspection I found that water heater #2 has a hot jacket. There must be a leak in the tank and the insulation has become waterlogged. The boiler room has a floordrain so it's not like it will fail one night and flood the basement but we can't leave the heater connected because either you'll burn a ton of gas trying to keep the tank hot and if you turn it off that means hot water from heater #1 has to go through the abandoned tank. It will need to be completely removed.
Since we no longer have a large shower area we should be fine with just one water heater.