Few appliances seem less important when they operate properly, or create more of a stir when they fail, than home water heaters. That being the case, it's important that you purchase the best unit you can and have it installed properly by a reputable plumber. However, you may not be privy to the wide range of choices available to you when it comes to water heaters.

Standard Fare
The most common type of heater on the market is a conventional storage model, though it is also the least efficient. These water heaters heat a tank full of water—anywhere from 20 to 80 gallons at a time—that you draw from when you turn on the hot water at the faucet. These models are probably the best choice for large households, since they can supply hot water to multiple sources without going cold. Keep in mind, however, that you are sacrificing efficiency for convenience. Storage heaters experience standby heat loss, meaning your heater constantly has to fire up to keep the water in the tank at the proper temperature. In simple terms, you pay a lot to heat water over and over again when the tank sits idle. Make sure your heater is well-insulated if you choose this type of model, and you'll be able to keep this heat loss to minimum.

Demand Heaters
The other popular option when it comes to heating your H2O is a tankless style heater. Demand water heaters run cold water directly past a heating element when you turn on the faucet, eliminating any standby heat loss that occurs by storing water in tanks. These heaters don't do as well in high demand situations, however, since there is a limited flow of hot water they can produce. You can counter that by installing multiple units, if you're set on demand heaters over conventional storage models.

Heat Pump, Tankless Coil, and Indirect Water Heaters
Heat pump, tankless coil, and indirect heaters also forego using a tank, though they utilize pre-existing heating sources in your home to do the work for you. This can mean circulating water through your heat pump, or past your furnace or boiler. These are great options in the colder months, since those appliances are already running around the clock, though they can lead to unnecessary and wasteful operation of your heating appliances when the weather turns warm.

Green Alternatives
If you live in one of the warmer areas of the country and get a lot of sun, consider a solar water heater for your hot water needs. There are multiple varieties of the eco-friendly alternatives, but the basic principle remains that you're heating your water with the sun, after which it is stored in a storage tank for use. Some combine forces with fuel based water heating methods while others are solar all the way. Regardless, a good solar heater is one of the most cost effective hot water solutions out there. The only real downside—cloudy days.

Final Thoughts
No matter which kind of heater you choose, remember that hot water costs money anyway you cut it. Conserve its use by not running hot water through faucets when it isn't necessary, take shorter showers, wash clothes and dishes in cold water when possible, and turn down your hot water heater when you're going to be gone for extended periods of time. Also, talk to an appliance retailer or plumber about matching the proper heater to your lifestyle, locale, and habits in order to get the most out of your new appliance.