The water heater is not a new concept where human history is concerned: throughout the ages, even as far back as ancient times, people have been employing various means and mechanisms to produce warm water for bathing in cold climates, and even the cruder techniques among these may be considered, to some extent, water heater applications.
Possibly the most well known water heaters from ancient times were those used by the Ancient Romans, who are famous for their baths. Some of these ancient structures remain even now and are tourist attractions. During the time of their operation, the baths were run by a water heating process we would consider rudimentary now, yet was quite ingenuous in those days. The Romans ran water into the baths by piping it from their aqueductsa plumbing development for which they may be creditedand used log or wood fires to heat the water before piping it into the bathing area.
The water heater we have today is vastly different, of course: now, when you speak of water heaters, you usually mean something that is capable of heating water in an uninterrupted flow from the cold tap source to the outlet for heated water. If we consider this to be the type of water heater whose history we are discussing, then the invention of the water heater is most often credited to an Englishman named Benjamin Waddy Maughan, a resident of London in the 1800s. In the latter half of that century, Maughan produced a water heater that people that time called The Geyser, and which worked by means of running cold water through hot wires. Geyser, of course, refers to the hot springs of Iceland, which can be quite dangerous due to their often unpredictable bursts of steaming hot water and the power with which this fluid is discharged. To that extent, geyser was indeed an appropriate name for Maughans invention: it had its fair share of danger owing to the fact that it lacked a vent for the hot gases that accumulated with its operation.
A somewhat safer version of the water heater was developed soon after in the United States by a Norwegian inventor. This inventor, Edwin Ruud, was deeply influenced by Maughans work and came up with his own version of the water heater, which soon grew to be very popular in the US. Nowadays, Ruuds manufacturing company still exists and produces various household and industrial products.
Sources :
Bay area Plumber
Tankless Water Heater Bay Area