Electric Hot Water Heaters

Water heating is a thermodynamic process that uses an energy source to heat water above its initial temperature. Typical domestic uses of hot water are for cooking, cleaning, bathing, and space heating. In industry, both hot water and water heated to steam have many uses.

Domestically, water is traditionally heated in vessels known as water heaters, kettles, cauldrons, pots, or coppers. These metal vessels that heat a batch of water do not produce a continual supply of heated water at a preset temperature. Rarely, hot water will be naturally occurring, usually from natural hot springs. The temperature will vary based on the consumption rate of hot water; the water becomes cooler as flow is increased.

Appliances for providing a more-or-less constant supply of hot water are variously known as water heaters, hot water heaters, hot water tanks, boilers, heat exchangers, calorifiers, or geysers depending on whether they are heating potable or non-potable water, in domestic or industrial use, their energy source, and in which part of the world they are found. In domestic installations, potable water heated for uses other than space heating is also called domestic hot water (DHW).

In the UK, electric water heating is often done by an immersion heater fitted near the bottom of the hot water tank. The immersion heater is a metal tube containing an insulated electric resistance heater which is usually rated at 3 kilowatts. Electric heaters may be tubular or cartridge type.[further explanation needed]

Water heaters that have residual hot water storage in a vessel/container heat, electrical water heaters can be a good match for an intelligent electrical power distribution system, heating when the electrical grid load is low and turning off when the load is high. This could be implemented by allowing the power supplier to send load-shedding requests, or by the use of real-time energy pricing.