Where we have our house parked, the main house needed to be repiped due to old decaying pipes. (And I got to point that out to the landlord since we were having some work done to make our house legal to park)
During the results of inspections etc..., the plumber and inspector were quite fascinated in the water heater in the garage. It dates to sometime in the 80s according to them. It was still OK, but apparently the work nudged it out of whack, so the house people are mentioning very short hot water time. They're trying to get it replaced, but apparently that is being difficult.
Doesn't really impact me since we have a tankless for the tiny house, but I seem to be the "responsible" person who can talk to plumbers/etc... while the landlord's son isn't around. (He lives there, but is on an extended trip)