Water is heated by element submerged in a self-contained, small, wall-mounted tank.
What are electric water heaters?
Electric water heaters work on a different principle as there is no burner, and no heat exchanger, no flue system is required. Electric water heaters typically employ two immersion elements. One is near the top of the tank and the other is near the bottom.
These elements provide the heat and, for the most part, the water configuration is the same as on a gas or oil system. Cold water is introduced near the bottom of the tank and hot water is drawn off near the top. This cold water near the bottom of the tank will activate the thermostat for the lower element. The lower element will come on and heat the incoming cool water. The upper element will still be surrounded with hot water and will be satisfied.
In a continuous flow system cold water entering the unit triggers a PCB, which in turn powers up the heating element. This sequence of events takes longer with electricity because it takes time for the elements to warm up, where as the effect of a gas flame is instant.