Electric Water Heater Element

Electric water heater element is an immersion heater element type that heats water in a tank type heater when energized with electricity. The electrical current that flows through heating elements is regulated by a safety device, called high limit.


The temperature of hot water is controlled by a thermostat. The most common electric heaters you will find, like Rheem, Kenmore, GE, Whirlpool usually have two thermostats and two heating elements.

These thermostats are manually adjusted, and they are surface mounted, in contact with the external portion of your electric heater.

Thanks to the electric water heater element where the electricity is used as a power source for heating, you can install the unit almost anywhere, which is not a case with gas heaters that depends on gas line.

Note: The thermostat, heating elements and internal wiring are factory installed. You should contact a licensed electrician for any electrical work on the heaters. Checking water heater elements is part of your regular maintenance, for keeping the unit in a good working condition.

Most residential electric heaters are non-simultaneous, working on 240 V and with 4500-watt power. Non-simultaneous term means that only one electric water heater element operates at a time.

electric water heater elementThese two heating elements are identical and the most common shape is U shape, screwed into a designated female threaded connection in the tank.

One is called the upper and the other is lower heating element, and the temperature is regulated by the upper and lower thermostat and high limit device.

High limit device is a safety feature; high limit switch disconnects the electrical current when the temperature reaches the unsafe level.

Since the temperature can be adjusted manually, just use a standard screwdriver. Most safety standards do not allow you to set a temperature above 120 F.


How electric water heater element works

Both electric heating elements, upper and lower one are submersed in the water of the water tank, while thermostat and high-limit switch are on the surface.

When the lower thermostat senses that the water temperature in the bottom portion of the tank is less than desired or requested, lower heating element gets the energy and the process of heating starts.

If the lower thermostat senses that the hot water has reached the set temperature, the electric current flow stops.

If more water is used than the lower heating element can heat, than the upper thermostat senses that the temperature in the upper part of the tank is lower that desired, electrical current energizes the upper heating element and it begins the heating cycle.

These non-simultaneous electric heaters have a slower recovery rate than other.

Simultaneous configuration means that more than one electric heating elements are working, and they require greater amperage protection.

Electric water heater element can be different in size, but the most common is 12" (300 mm). The electrical and wattage rating is indicated at the front of the heating element. Use the same configuration and/or model when replacing the old heating element.

Note: When you compare electric vs. gas heaters it is helpful to know the relation between power units; 1 kW is 3412 BTUs.

If you need an electric water heater that heats water faster than the one you already have, you should consider higher wattage of heating element.

Checking electric water heater element

If your hot water is not hot enough that doesn't mean that you have to replace the whole unit. You might have defected heating element. Since there are two electric heating elements, you should check them both so you will know for sure which one doesn't work. Water heater element testing have to be the first step when troubleshooting the electric unit which doesn't produce hot water.

Checking water heating elements is easy; check the working condition by placing an Amp clamp on one of the wires that are connected to the tested element.

Turn the temperature up on the tested heating element and down on the other one. Now, you want the electric water heater element that you test to activate.

Open up hot water tap so the heater can start working. At the same time cold water gets into the unit and the thermostat senses the change in the temperature and it clicks when it activates.

Your Amp meter indicates is there a current flow. If not than you have a defective electric water heater element and it needs replacement. Check the other heating element as well.


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