How Electric Tank Water Heaters Work

There are many things involved when transferring heat into water. Electric water heaters use a thermodynamic process in order to effectively heat water above its original temperature. There are a few basic pieces that make up a standard electric tank water heater's operation.

The element is the part of tank water heaters that allow a current to flow through the inner wire. The element is made up of an inner wire surrounded by a kind of filler material and enclosed in either stainless steel or copper. The thermostat allows electricity to run through the inner wire and create heat. This heat is then absorbed by the water. Elements meet specific heating requirements by having different wattages and materials available. All hot water heaters use elements. When installing new electric water heaters, or refilling ones currently in use, it's important to make sure the tank is full before applying power to the elements. If you do not do this, the element will burn out.

Standard electric water heaters have a control circuit that consists of a manual reset high limit switch, a lower and upper thermostat, two heating elements, and wires. When the power turns on, the upper element energizes and heats the water in the upper third of the tank. When this portion is hot, the lower thermostat is switched on and the lower element heats the lower portion. All water heaters have a cold inlet that allows cold water to enter the tank if the water gets too hot.

Cold water then mixes with the hot until the thermostat setting temperature is reached. If the upper element burns out, electric water heaters will cease to work because the upper thermostat will never be satisfied and therefore never kick on the lower element.

Electric water heaters have a maximum high temperature limit of 170 degrees Fahrenheit. If the water in the tank reaches this, the high limit switch will be tripped. This will turn off the elements until the water lowers in temperature. On most electric water heaters, this switch can be reset by pushing the red button above the upper thermostat. Electric water heaters also come in a single element model. The single element is located at the bottom of the tank and is controlled by a single thermostat. These models still have the high limit switch.

In the UK, electric water heaters often have an immersion heater located near the bottom of the water tank. An immersion heater is a metal tube, rated at 3 kilowatts, that contains an insulated electric resistance heater. One way of saving on energy costs is to use a water heater jacket during the winter months. The extra insulation will maintain the water heat while using less electricity. You can also save on electricity by using electric water heaters with a high insulation rating. Electric water heaters are great for families of all sizes. This standard form of tank water heating is traditionally used in most residences. Once you determine your desired capacity, it's easy to find a great electric water heater.

Electric Water Heaters