The idea of a hot water heater that does not store water doesn't make sense to some people but when you consider how both systems work, you can begin to see how the tankless system has an advantage over the old standard style water heater most people are used to seeing in a home. The efficiency and reliability of a tankless system can exceed that of the traditional hot water tank and will more than likely save you money as well.
How Water Heaters Work
The traditional hot water heater that is installed in many homes, and has been for the last fifty years, uses one, two, or even three heating elements in the tank to heat the water after the tank is filled. The heating elements are electric and once the tank is filled with water, they come on and stay on until the water in the tank is hot. Once the water starts to cool, they come back on to reheat that same water again and the process is repeated over and over again until the hot water is needed. The alternative is to use gas to heat and reheat the water instead of the electric heating elements. The gas is a little more efficient but the process is the same, continuing to heat water throughout the day.
How Tankless Systems Work
The idea for a tankless water heater is not new. In fact, they have been in use in many parts of Europe for many years. The system is made up of a heating unit that contains a heat exchanger and burner or heating coil that works together to provide hot water on demand. The water is heated when it is needed rather than heated and reheated over and over. The cost is the system is about two or sometimes even, three times more expensive than a traditional system but the cost savings over the year will pay for the system pretty quickly.
Point Of Use Or Whole House Systems
The two most common systems are whole house systems that provide hot water to the entire home and point of use systems that feed one or two faucets. With the whole house systems, the water has to come from the heat exchanger to the faucet that is opened so there can be some delay in getting hot water but once it gets there, it will stay hot until you shut off the tap. Point of use systems are smaller and installed near the faucet so one small point of use heater could be installed in the bathroom to feed the shower and sink, for instance. Putting the system close to the faucet means there is very little if any lag in getting hot water at the tap and they are small enough to go under a sink or in a closet where they are not seen.