Most of the work was done Tuesday, but I didn't get hot water until Wednesday. Even so, I now have a brand spankin' new furnace and water heater.
The duct guy should be out in a day or two to replace the ducts upstairs. And I'll soon buy new doors for the utility closet. The old doors had no ventilation slats so they were useless and are long gone.
The water heater is a gas powered, electric ignition, tankless system. It heats 3 gallons per minute. I went with this partially to free up some space but largely because with a hot water tank you have to keep reheating the water and wasting energy.
The shower had an odd smell. Not bad. Just different than before.
Now that the old water tank is out of the way it turns out there's some storage I didn't know about at the very foot of the stairs.