Are you thinking about upgrading from your current water heater to a tankless variety? Tankless water heaters, sometimes called demand or instantaneous water heaters, have been hailed as the best way to conserve energy (and lower costs) and still have hot water delivered where you want, when you want.
Tankless water heaters are available in both gas heated and electric models. Electric models can provide a continual flow of 110 degree water at a rate of about 2 gallons per minute. This is enough to run a low flow shower head comfortably. If you are planning on using hot water in more than one location at a time, running a dishwasher and taking a shower for instance, you will need multiple tankless heaters or a gas powered model. Gas powered models can usually provide 4 to 5 gallons per minute at the 110 degree temperature.
One of the most common uses for this new technology is to bolster the production of a solar water heater. If the solar panels are raising the temperature of the ambient water by 40 degrees, this can result in the tankless heater being able to double its throughput.
Maintenance on tankless water heaters is usually limited. They are built to
last 20 years or more, and components that fail are easy to replace. The initial cost of installation is often mitigated by the savings that can be made in energy costs in the first ten years.
The U.S. Department of Energy division of Energy Efficiency and Renewable Energy says, "homes that use 41 gallons or less of hot water daily, demand water heaters can be 24% - 34% more energy efficient than conventional storage tank water heaters." They also suggest that by using tankless heaters at every hot water outlet, you can save up to 50%.