Tankless electric water heater is a type of electric water heater, different from storage electric water heater. It does not require a large storage container to heat water, and does not need or rarely stores hot water. Instead, it rapidly heats water as it flows through a high-power heating element, providing hot water directly from the pipe. Storage electric water heaters use a large water tank to resolve the contradiction between low heating power and high water demand, while tankless heaters unify the two by quickly heating the incoming water with high power.
Features of tankless electric water heaters
Storage electric water heaters have relatively low installation requirements but are bulky; the stored water temperature is generally high; heating time is long, and sometimes there is insufficient hot water or leftover hot water, causing waste; to meet different consumer needs, multiple capacities must be designed, resulting in many models.
Corrosion and scaling of the storage tank liner have always been a prominent issue hindering industry development, especially in areas with poor water quality. Tankless electric water heaters use flow heating technology, basically requiring no hot water storage, so they are compact and lightweight. Their design is free from the constraints of large size, offering better aesthetics and fashion. Tankless electric water heaters have high power and fast heating speed, requiring no preheating, providing hot water instantly, and are convenient to use. Since tankless heaters have no liner, they do not need insulation, resulting in minimal heat loss and energy savings.
Another major advantage of tankless heaters is the low heating water temperature. Taking the well-known brand Greenmus as an example, tankless electric water heaters basically avoid the corrosion problem caused by water. Gas water heaters were the earliest type of water heater in China. They use gas or natural gas as fuel, generating heat through combustion to heat water. The outlet water temperature can be adjusted by regulating the water flow. Heating speed is generally fast, but the exhaust gases such as carbon monoxide and carbon dioxide produced by gas combustion are directly discharged indoors, easily causing gas poisoning. To prevent such tragedies, gas water heaters have been continuously improved, introducing forced exhaust, flue-type, and balanced gas water heaters. These heaters have greatly improved safety, but installation requires drilling holes in the wall for exhaust pipes, which is inconvenient and damages the wall aesthetics.
Tankless electric water heaters are easy to install and have significant advantages in aesthetics. However, tankless electric water heaters generally have high power, which imposes certain conditions for use. They require a dedicated copper core circuit of at least 4mm² and a meter of 20A or more, preferably with an air switch. Due to these conditions, such water heaters are not yet widely adopted.
Additionally, due to the lack of popularity, low production volume, slow market development, the cost and unit price of tankless heaters are still relatively high. Competition is not as intense as in the storage water heater market, leading to a mix of good and bad products. Some irresponsible companies produce substandard products with unstable performance, rapid power decay, and short service life.
PS: Each has its pros and cons; choose according to your needs. 1. Disadvantages of electric water heaters: Due to the working principle of heating water in a storage tank via heating elements, they consume more electricity. The storage tank makes them bulky and takes up space. Long-term use requires regular descaling to prevent bacterial growth. Additionally, they need preheating and have limited hot water capacity. Advantages: Electric water heaters are cleaner and safer than gas water heaters, with fewer installation restrictions—they can be installed wherever there is electricity. Since they do not require separate room installation, temperature adjustment is more convenient than gas heaters. 2. Disadvantages of gas water heaters: Gas water heaters require separate room installation, making the installation process more complicated than electric heaters. Since gas is supplied, there is a risk of gas leakage, producing harmful gases that endanger health. Moreover, if the kitchen and bathroom are far apart, gas water heaters may cause slow water flow. Gas water heaters also have high water pressure requirements, so they are not recommended for high-rise buildings. Advantages: Gas water heaters are generally cheaper than electric ones, heat water quickly, and maintain stable water temperature. They are usually compact and provide unlimited hot water, as they heat water on demand without needing long preheating. They can be used anytime, making them more suitable for large families.
