The 10 Best Energy Efficient Electric Water Heater in 2024 - Features, Reviews and FAQs

CONTINUOUS FLOW – Advanced Flow Control patented technology invented by Stiebel Eltron, automatically maintains water temperature for constant comfort. It’ll reduce flow slightly if hot water demand exceeds capacity. Hot showers will never be interrupted again

SPACE & ENERGY SAVER – Its small, sleek white design saves space yet still provides endless hot water for your whole house, and no venting is required. Eco friendly unit saves energy with auto-modulation and the ability to electronically control water flow. Savings monitor even shows how much you save on energy costs

EASY OPERATION – Electronic switch activates the hot water heater and it’s noise free while in use. Has a digital temperature display and preset temperature and memory buttons, while the interior solid copper heating system does all the power work

TEMPRA 15 PLUS – This specific model is 14.4kW, 240V, requires a min recommended electric service of 100 A, and offers an output water temperature of 68° to 140°F. Check our guides below to compare features of our various Trend and Plus models, each available in different kW levels

WARRANTIES INCLUDED – Stiebel Eltron’s top-rated electric tankless water heaters perform with the highest standards for comfort and reliability. Our 7-Year Leakage and 3-Year Parts Warranties are included with purchase

☼ Instant Hot Water: The 8kW electric tankless water heater supplies instant & endless hot water of 108℉ or higher with no waiting for preheating or temperature fluctuations. perfect companion for faucet and sinks, bringing you perfect experience of comfort and relaxing.

☼ Save Energy: Water is only heated when you need it, not stored in a hot water tank. The self-modulating temperature technology only uses energy to heat up water while you are using it to save up to 50% on water heating energy compared to a typical tank water heater.

☼ Save Space: A traditional water heater in the basement or utility closet takes up a ton of space. This wall-mounted water heater uses 90% less space than a hot water heater with a tank. Compared to our next-largest 9kW water heater, this 8kW unit is 30% smaller with only 3,412 BTUs.

☼ Important Note: In order to install 8kW Electric Tankless Water Heater, it will require a 240 Voltage, 40 AMP circuit breaker. Please check to confirm that your breaker panel meets these specifications before purchasing.

☼ Safe To Use: With high temp protection, dry heating protection, and electrical leakage protection you can rest easy knowing you have safe, on-demand hot water to use on your schedule. The electric and fluid systems are completely separated to prevent electric leakage and water pipe corrosion.

CONVENIENT HOT WATER HEATER: 7 gallon point-of-use mini-tank fits under your sink to provide hot water right where you need it. Thermal efficiency is 98%. Dimensions : 17.5 W x 17.5 H x 14.5 D Inches

INSTALLED VERTICALLY OR HORIZONTALLY: This larger model can be mounted vertically (5.1 gal. of water supply) or horizontally (7 gal. of water supply)- vertical orientation is installed with the cold and hot lines on top of the unit

RELIABLE WATER SOURCE: Easily hard-wire the 7-gallon model to provide the on-demand reliable water source your home or office needs

IMPORTANT INFORMATION: Heating capacity of 1440 watts and a temperature range of 65-145°F max. Operating pressure-150 psi. Water fittings-3/4 inch Male NPT. Electrical requirements (Amp 12A/Volts 120)

EASILY MOUNTED: Can be shelf or floor mounted. Wall mounting available in vertical orientation only (water connections on top) - bracket included. Simply tap into the cold water line and install the water heater directly at the sink to provide hot water

Endless on-Demand Hot Water; Consistent hot water when you need it that never runs out; Continuously monitored water temperature and controlled flow rates ensure efficiency and consistent performance within 1 degree of selected temperature

Save Space; EcoSmart tankless electric water heaters are 90% smaller than traditional tank heaters; may be installed on wall or at point of use; Dimensions 17 x 17 x 3.75 inches 

Save Energy; EcoSmart tankless electric water heaters are 99% thermal energy efficient; Only heats water when called unlike a tank heater that maintains water temperature even when not being used. Save up to 50% in water heating costs according to the Department of Energy

EcoSmart ECO 27 Sizing; Refer to the sizing map. Requires 3x40 AMP Double Pole Breaker, 27-kilowatt tankless electric water heater ideal for providing hot water for whole home applications; provides between 2.7 and 6.5 gallons-per-minute depending on the inlet water temperature; refer to the sizing guide to select the proper solution

Warranty and Certifications; Limited Lifetime Warranty on electronics, exchanger and element; UL-499 certified; ETL Listed

Required Breaker Quantity: Three 40 Amp Double Pole

Recommended Electrical Panel: 200 Amps

NEVER run out of hot water with an ECOSMART tankless water heater.

Save up to 12 cubic feet of storage space.

Digital temperature control in 1-degree increments gives users complete control of hot water

CONVENIENT HOT WATER HEATER: 2.5 gallon point-of-use mini-tank fits under your sink to provide hot water right where you need it. Thermal efficiency is 98%. Dimensions : 13.75 W x 13.75 H x 10.75 D Inches

LONG LASTING QUALITY: This electric water heater is easy to maintain and has premium glass-lined material for a long service life. (Amps 12A, Volts (VAC) 120)

INDEPENDENT INSTALLATION: 36-37" cord plugs into a 120 volt outlet for independent installation or in-line with a large hot water source

FAST RECOVERY RATE: Eliminates long waits for hot water at your sink, get on demand hot water at your every need (supplies up to 2 sinks at a time)

EASILY MOUNTED: Can be shelf, wall or floor mounted (bracket included); simply tap into the cold water line and install the water heater directly at the sink to provide hot water

The product is highly durable

The product is easy to use

Manufactured in China

Amperage (amps): 75. Activation flow: 0. 3 GPM. Flow Rate @ 35 F Rise (gallons/min): 3. 51 gal (US)/min

The product works and is compatible with 2 X 40 AMP (DP) breakers and 2 X 8 AWG wire

Lifetime warranty for residential use

Save up to 60% on your water heating costs with the most advanced, self modulating technology available

Never run out of hot water with an ECOSMART tankless water heater.

Save up to 12 cubic feet of storage space.

Digital temperature control in 1-degree increments gives users complete control of hot water

75 A

Endless On-Demand Hot Water; Consistent hot water when you need it that never runs out; Continuously monitored water temperature and controlled flow rates ensure efficiency and consistent performance within 1 degree of selected temperature

Save Space; EcoSmart tankless electric water heaters are 90% smaller than traditional tank heaters; may be installed on wall or at point of use; Dimensions 11.5 x 8 x 3.75 inches

Save Energy; EcoSmart tankless electric water heaters are 99% thermal energy efficient; Only heats water when called unlike a tank heater that maintains water temperature even when not being used.

EcoSmart ECO 11 Sizing; 13-kilowatt tankless electric water heater ideal for providing hot water for a bathroom, small sink, office breakroom and other point-of-use or low-flow applications; provides between 1.3 and 3.1 gallons-per-minute depending on the inlet water temperature; refer to the sizing guide to select the proper solution

No More Wait for Hot Water - Point of use 4 gallons mini tank water heater provides instant hot water where you need it with fast recovery, reducing standby loss. Thermal efficiency up to 99%

Easy Installations - Dimensions 14.5"W x 14.5"H x 12.9"D compact design, can be wall or floor mounted under sink / counter, plug into a standard 120V outlet, no special wiring required. Nominal current 12amps

Adjustable Temperature - Thermostat with 3 temperature level settings, range from 50°F to 149°F with high temperature limit protection, also a freeze mode to prevent tank from freezing

UL Certified & Durable - Enamel Coating Glass-lined tank for great insulation and preventing leaking, CASH USA made Temperature & Pressure Relief valve included, UL certified ensuring a safe long service life

Specifications and Warranty - Dimensions: 14.5"H x 14.5"W x 12.9"D; Weight:19.8lbs; Water connections: 1/2" NPT, Electrical requirements: 1.44 kW at 120 volts, plug-in connection with 2 feet power cord; Max water pressure:150PSI; Nominal current: 12A. 3-year Limited Warranty for the tank, 1-year warranty for parts and 24hours customer service

ON/OFF Dial Control with adjustable digital temperature display

Self-modulating power control

24kW Model Flow Rate: up to 5.9 GPM for RTEX-24

Bottom 3/4" NPT water connections

On demand, consistent and continuous hot water

[Endless On Demand Hot Water] - Consistent hot water that never runs out when you need it. Continuously detect water temperature and flow rate to ensure efficient heating and stable performance within 1°F of your selected temperature. REQUIRES 2 SET of Double-pole 30AMP Breakers

[Last Long & No Leaking] - Alloy metal housing & water ports, heating element separated from water tube significantly reducing scale, corrosion and mineral buildup on the element, achieving better performance and low maintenance.

[Save Money and Space] - Self-modulating technology regulating the amount of energy required to heat water only when you need it with 99% efficient, saving up to 60% on water heating cost comparing to traditional tank water heater. Wall mounted compact size with no water tank, convenient for any spaces, saving floor space and fitting into tight spaces

[Easy Installation & Safety Protection] - ETL certified with overheating protection, auto stop heating when detecting no water, quality workmanship for leakage protection

[Installation] - 11 kilowatts at 240V draws max 46amp, 1/2” NPT male ports, 12AWG wire to 2 Double-pole 30AMP breakers, ideal for providing hot water for a bathroom, small sink, office break room and other point-of-use or low-flow applications