Tankless water heaters offer savings on the cost of heating water and require less space than conventional water heaters. Tankless heaters do cost somewhat more in the initial purchase price but can save on repair costs down the road. Understanding how they work can help you determine if a tankless water heater is a better choice for you.
Tankless water heaters heat water on a demand or as needed basis. Small under-sink or sink mounted units have become popular in many kitchens for obtaining near boiling water for cooking and hot drinks. When a faucet is turned on for hot water, water will begin to flow through the system. The water flows past the heating element and quickly becomes hot. As soon as the hot water faucet is turned back off the heating action stops. While the water that first flows from the tap will be colder it does not take much longer to become warm than it would with a conventional water heater.
Conventional water heaters keep an entire tank of water heated at all times. When the water inside drops below a set temperature the unit begins heating again. This means that gas or electricity is being used whether or not there is any need for hot water. In addition if all the water in a conventional water heater is depleted users must wait until the system refills and reheats to the desired temperature. Tankless heaters can continue to provide hot water long past any gallon restraints of tank units.
Tankless water heaters can be purchased in all size ranges from whole house units to point of use models. Larger homes may benefit from a combination of units if there is a high demand for hot water. Smaller tankless water heaters can also be beneficial for homes with bathrooms that are farther away from the main water heater than is desirable. The water will not have cooled by the time it finally reaches the tub. They can also be added to laundry areas to assure hot water for a washing machine.
Tankless water heaters can be purchased to work with either gas or electric hook up so major changes are not needed for installation. The lack of a large holding tank allows them to be placed in smaller areas and they are commonly hung on a wall. The lack of a tank also increases the longevity of the water heater. There is no tank to eventually rust and the lack of rust build up keeps the water cleaner. The maintenance requirements are less and parts are easy to replace providing the owner with additional savings.
When considering the type and size of a tankless heater to purchase estimate the total amount of hot water that may be used in your home at one time. Homes with only one or two bathrooms, a kitchen sink, dishwasher and washing machine will usually not need more than an average whole house system. Homes that have more bathrooms and other additions may require one or more point of use systems in addition to the main unit.
References:
http://tanklesswaterheaterguide.com/