10 Best Electric Tankless Water Heater

The Stiebel Eltron DCE-X Premium Compact Instant Water Heater is designed for maximum energy efficiency and precise temperature control, making it suitable for showers. With a power rating of 10/12 kW, it can handle quick heating needs effectively.

The large backlit multifunction display aids in easy operation, while the fully electronic closed-loop control ensures consistent temperature delivery. The heater also operates efficiently in ECO mode, potentially saving on energy costs.

Its compact design (10.9 x 21.7 x 37.2 cm) and light weight (2.5 kg) make it suitable for small spaces and easier to install. The included components, like cable grommet and twin connectors, facilitate straightforward installation. If you're seeking an efficient and easy-to-install water heater for showers in tight spaces, this model holds strong promise.

The Rheem 18kW 240V Tankless Electric Water Heater is a solid choice for those needing an efficient and space-saving water heating solution. With a flow rate of up to 4.4 GPM, it can handle multiple outlets simultaneously, which is suitable for a small to medium-sized household. The LED display with external digital thermostatic control allows you to adjust the temperature accurately by 1 degree, making it easy to get the perfect water temperature.

The heater’s self-modulation feature is particularly impressive, as it adjusts power usage based on hot water demand, improving energy efficiency (rated at 99.8%) and potentially reducing electricity bills. The unit uses durable copper immersion heating elements that are field serviceable, meaning they can be replaced if necessary, enhancing its longevity. Installation is relatively straightforward with bottom 3/4 inch NPT water connections and threaded design for easy replacement. However, some users might need professional help for installation due to electrical requirements.

Measuring 36.83 x 36.83 x 46.36 cm and weighing 6.7 kg, it’s compact and can be wall-mounted, saving valuable space. The product has a strong customer rating (4.3 out of 5 stars from 1,848 reviews), indicating general satisfaction. One drawback is that it might struggle in very cold climates where the incoming water temperature is low, potentially requiring a higher kW unit to achieve the desired temperature rise. Additionally, while it is efficient and reliable, it is relatively more expensive upfront compared to traditional tank water heaters. The warranty and support from Rheem generally receive positive feedback, offering peace of mind to buyers.

The STIEBEL ELTRON instant electric hot water heater boasts a selectable output of 18/21/24 kW, offering flexibility depending on your hot water needs. It supports a flow rate of up to 10.7 litres per minute, handling multiple points of use simultaneously, such as showers and sinks, making it suitable for both small and medium-sized households.

The 3i technology ensures accurate temperature delivery, and the LCD and rotary selector make it easy to adjust and monitor the temperature precisely. Additionally, the device includes several safety features like dry burn protection, overheat protection, and an integrated error code indicator, enhancing its reliability and safety profile. Its compact size and wall-mounted design allow for easy installation in various locations.

Potential drawbacks include its power requirements, as it needs a 400-volt connection, which might necessitate electrical upgrades in some homes. The energy efficiency of the unit is not explicitly stated, but tankless water heaters typically offer better energy savings compared to traditional tank heaters. The STIEBEL ELTRON water heater is a strong contender for households looking for a reliable, flexible, and compact hot water solution, provided they can accommodate its electrical requirements.