Instantaneous or continuous flow water heaters are designed to deliver a steady stream of heated water for a bath, sink or shower. Each time a tap is turned on, water is heated instantly by electricity and then flows to the outlet.
Another good thing about on-demand hot water systems is that they could last longer than conventional storage heaters. Instant units can last up to 20 years and the life expectancy might get even longer because of their easily replaceable parts. In contrast, storage water heaters can last 10 to 15 years.