Most of Little Havana was built between the 1920s and the 1950s, and in a great many of those houses the water heater is not really in the house. It sits in a utility closet at the back, off the patio, or in a lean-to against the rear wall beside the washing machine and the water service.
Calle Ocho and the blocks behind it
The commercial spine is SW 8th Street, Calle Ocho, running west past Maximo Gomez Park at 15th Avenue and the Tower Theater a block further on. Behind it the residential streets are bungalows, duplexes and small apartment buildings on narrow lots, usually with a driveway down one side and a rear yard that has been built over at some point. Those additions are where the complications live: a converted garage or a casita that was wired and plumbed after the fact, a heater shifted to make room for it, and a vent run that no longer meets the wall the way it was meant to.
Gas, shutoffs and a mixed plumbing history
Many units here are gas, and the closet they stand in was sized for a smaller appliance. A modern replacement is taller and wider, which changes the clearance to the vent and to the door. The gas connection, the sediment trap and the shutoff are checked before the old unit comes out, because a valve that has not been turned since the house was built is not something to discover halfway through a job.
The interior plumbing is often a mixture. Galvanised service lines in some houses have been partly replaced with copper or PEX over the years, and a heater starved by a choked line will look like a failed element until pressure and flow are measured rather than guessed.
Access matters as much as the appliance. A tank has to get from the street to a rear closet without being carried through the kitchen, and where there is no driveway it comes in by hand. Permits for the work come from the City of Miami, which covers Little Havana. Start on the contact page and say whether the unit is at the rear, in a garage or inside the house.