While traditional water heaters remain the best choice for some, tankless models save space and can help reduce monthly heating bills. Before switching, shoppers should choose between a gas or electric model. High-end gas models are usually more powerful but are also more expensive and challenging to install.
Many homeowners prefer to avoid gas for safety reasons. Gas tankless water heaters typically aren’t as efficient as electric models, so that’s another reason to choose an electric tankless water heater. Here are the best electric tankless water heaters available based on specifications, features, and customer reviews.
- BEST OVERALL: Stiebel Eltron Tempra Tankless Water Heater
- RUNNER UP: EcoSmart ECO 27 Electric Tankless Water Heater
- BEST BANG FOR THE BUCK: Thermomate Tankless Water Heater
- BEST FOR SMALLER HOMES: EcoSmart ECO 11 Electric Tankless Water Heater
- MOST VERSATILE: Stiebel Eltron 240V DHC-E12 Single/Multi Water Heater
- BEST POINT OF USE UNIT: Ecotouch Tankless Water Heater
- ALSO CONSIDER: Rheem RTEX-18 240V Electric Tankless Water Heater
How We Chose the Best Electric Tankless Water Heaters
We researched the best electric tankless water heaters in a variety of categories and chose options with high customer satisfaction. The list factors in maximum temperature, maximum flow rate, efficiency rating, and special features included by the top brands.
The majority of the featured units offer water temperatures up to 140 degrees Fahrenheit. The selected water heaters have a range of flow rates between 1.5 and 7.5 GPM to accommodate the water needs of different households. Most units have an efficiency rating of 99 percent and above. Additionally, we prioritized water heaters with digital thermostats, durable metal components, and self-modulating technology. A few units are also UL and CSA certified for reliable performance.
Our Top Picks
Our top picks come from a variety of leading manufacturers and have been divided into different categories to make it simple to find the best electric tankless water heater for a particular situation.
Photo: amazon.com
The Stiebel Eltron Tempra is among the most powerful electric tankless water heaters on the market, providing a maximum of 7.5 GPM, which should be sufficient to provide enough water for four showers running simultaneously. It can heat water to 140 degrees Fahrenheit, well above the U.S. Department of Energy’s (DOE) maximum recommendation for household water temperature of 110 degrees Fahrenheit.
It’s also highly efficient. Given that no system is 100 percent perfect, a rating of 99 percent efficiency makes the Stiebel Eltron among the best available. Auto modulation minimizes temperature fluctuations, and the unit runs virtually silently. Preferred temperature can be preset into memory using the digital display.
This 36 kW model requires a 240V supply and three 50 amp breakers. There are many Stiebel Eltron models in the Tempra range, offering high-quality solutions for installations of all kinds. Safety is recognized by independent Underwriters Laboratories (UL) and Canadian Standards Association (CSA) certification.
Product Specs
- Model: Tempra 36
- Maximum Temperature: 140 degrees Fahrenheit
- Maximum Flow Rate: 7.5 GPM
- Efficiency Rating: 99 percent
Pros
- Auto-modulation minimizes fluctuations in water temperature
- Near-silent operation provides enough heat for four simultaneous showers
- Can preset preferred temperatures
- UL and CSA safety certifications
Cons
- Some reports of manufacturing defects
Get the Stiebel Eltron Tempra electric tankless water heater on Amazon or at The Home Depot.
Photo: amazon.com
The EcoSmart electric tankless water heater is a compact unit that still offers competitive performance with a maximum of 6.5 GPM. It also has a minimal activation requirement of 0.3 GPM, so users don’t have to turn faucets on full power to get hot water. A less responsive electric water heater would waste water and electricity used for heating, but this one provides optimal control.
Like many other leading devices, it uses flow modulation when heating water. This ensures optimal energy conservation while ensuring that changes in supply temperature or pressure have no impact on hot-water output. The maximum achievable temperature is 140 degrees Fahrenheit and its energy efficiency is 99.8 percent.
Running at 27 kW, the EcoSmart ECO 27 requires a 240V supply and three 40 amp breakers. The device is both UL and CSA certified for safety.
Product Specs
- Model: ECO 27
- Maximum Temperature: 140 degrees Fahrenheit
- Maximum Flow Rate: 6.5 GPM
- Efficiency Rating: 99.8 percent
Pros
- Highly efficient unit with a rating of 99.8 percent
- Minimal activation requirement of 0.3 GPM does not require full water pressure for heat
- UL and CSA certified for safety
Cons
- Some complaints about product quality
Get the EcoSmart ECO 27 electric tankless water heater at Amazon, Ace Hardware, or The Home Depot.
Photo: amazon.com
The budget-friendly 18 kW Thermomate Tankless Water Heater is an economical solution designed to provide virtually instant hot water for up to three different applications. Despite the low cost, there’s still a digital thermostat adjustable in single-degree increments and self-modulated control for stable temperature output, plus maximum energy savings.
The heating elements run adjacent to the water supply rather than being immersed, reducing scale and corrosion for longer life. There is overheating protection, dry-heat protection in the event of interruption to water supply, and the unit is Electric Testing Laboratories certified for safety.
The Thermomate range also offers low-cost electric tankless water heaters at 11 kW and 27 kW, providing money-saving solutions for a variety of hot-water demands. This 18 kW unit requires 240V and two 40A breakers. Combined with a gas heater, it could also provide an efficient solution for hot water and warmth in a garage or basement.
Product Specs
- Model: 18kW
- Maximum temperature: 140 degrees Fahrenheit
- Maximum flow rate: 3.51 GPM
- Efficiency rating: 99.8 percent
Pros
- Budget-friendly unit provides enough power for up to 3 applications
- Low-maintenance heating elements less likely to corrode
- Digital thermostat is adjustable in single-degree increments
Cons
- Modest flow rate might not meet demands of multi-bath homes
Get the Thermomate electric tankless water heater on Amazon or Thermomate.
Photo: amazon.com
Those who live in compact modern homes will want to take a close look at the EcoSmart ECO 11. Rated for a maximum of 3.1 GPM, this affordable unit can provide constant hot water for a shower and low-flow faucet simultaneously. It is one of few electric tankless water heaters that uses the accurate UEF standard, with outstanding efficiency of 99.8 percent.
As with all the models in the EcoSmart range, the ECO 11 has self-modulating technology. The DOE estimates it saves around 50 percent on hot-water costs per year. The digital display provides temperature-control adjustment in 1-degree steps, anywhere from 80 degrees to 140 degrees Fahrenheit. The EcoSmart ECO 11 is a 13 kW device requiring 220V and a single 60A breaker.
Product Specs
- Model: ECO 11
- Maximum Temperature: 140 degrees Fahrenheit
- Maximum Flow Rate: 3.1 GPM
- Efficiency Rating: 99.8 percent
Pros
- Affordable unit that saves up to 50 percent on annual hot water costs
- Highly efficient model provides simultaneous heat for a shower and low-flow sink
- Self-modulating technology provides stable temperature output
- Digital temperature control adjusts in 1-degree increments
Cons
- Some complaints about warranty and customer service
Get the EcoSmart ECO 11 electric tankless water heater on Amazon or at The Home Depot.
Photo: amazon.com
With a maximum flow rate of around 2 GPM, the Stiebel Eltron DHC-E12 can be used for single or multipoint installations. While often fitted for sink use, it’s equally capable of providing hot water for a low-flow shower. It’s a great choice for remodels and equally good for permanent fitting in boats and RVs. With its renowned reliability and durability (capable of surviving seismic activity), it’s also popular in commercial environments such as offices, warehouses, and gas station restrooms.
The Stiebel Eltron DHC-E12 has an energy efficiency rating of 99 percent. It uses microprocessors for advanced flow control, ensuring constant temperature anywhere from 86 degrees to 140 degrees Fahrenheit. It requires a 240V supply and uses a single 50A breaker.
Product Specs
- Model: 230628
- Maximum Temperature: 140 degrees Fahrenheit
- Maximum Flow Rate: 2 GPM
- Efficiency Rating: 99 percent
Pros
- Ideal for sinks and low-flow showers, especially in boats, RVs, and offices
- Reliable and durable design; capable of withstanding seismic activity
- Microprocessors for advanced flow control
Cons
- Low flow rate; doesn’t meet the needs of most homes
Get the Stiebel Eltron DHC -E12 electric tankless water heater on Amazon or at The Home Depot.
Photo: amazon.com
All electric tankless water heaters are relatively compact, space-saving units, but at just 11 inches high by 7.5 inches wide by 2.35 inches deep, this Ecotouch unit really can go just about anywhere. Despite the diminutive dimensions, this unit has 1.5 GPM and an efficiency rating of 98 percent. It can provide constant hot water at up to 116 degrees Fahrenheit.
It’s also tough enough for commercial uses with a fire-retardant case and tempered-glass front panel. It is self-modulating for temperature stability and has protection circuits for overvoltage, overheating, and leakage. The single-point unit can be fitted at any angle, so it will function perfectly well on a boat in motion, for example.
The Ecotouch requires a 240V supply and uses a single 30A breaker.
Product Specs
- Model: N/A
- Maximum Temperature: 116 degrees Fahrenheit
- Maximum Flow Rate: 1.5 GPM
- Efficiency Rating: 98 percent
Pros
- Compact unit suitable for small spaces
- Fire-retardant case and tempered glass front panel; great for commercial use
- Self-modulating for temperature stability
- Protection circuits for overvoltage, overheating, and leakage
Cons
- Low flow rate; not ideal for showers
Get the Ecotouch electric tankless water heater on Amazon.
Photo: amazon.com
Rheem has tremendous experience with both gas and electric tankless water heaters. The high-quality RTEX-18 is rated for up to 4.4 GPM and offers advanced self-modulation, helping it achieve an efficiency rating of 99.8 percent. It can raise water temperature for one or two showers well beyond the recommended 110 degrees Fahrenheit level, making it an impressive yet economical choice for modest homes.
It is widely recognized as being easy to install. Operation is simple, with a clear display and large dial offering control in single-degree increments.
Brass-topped heating elements offer high durability and are easy to replace should the need arise. This Rheem model is an 18kW unit requiring a 240V supply and two 40A breakers.
Product Specs
- Model: RTEX-18
- Maximum Temperature: 140 degrees Fahrenheit
- Maximum Flow Rate: 4.4 GPM
- Efficiency Rating: 99.8 percent
Pros
- Easy-to-operate control dial with digital display
- Advanced self-modulation for 99.8 percent efficiency rating
- Simple installation
- Brass-topped heating elements are durable yet easy to replace if needed
Cons
- Some complaints about performance
Get the Rheem electric tankless water heater on Amazon or at The Home Depot.
A Recap of Our Recommendations
- BEST OVERALL: Stiebel Eltron Tempra Tankless Water Heater
- RUNNER UP: EcoSmart ECO 27 Electric Tankless Water Heater
- BEST BANG FOR THE BUCK: Thermomate Tankless Water Heater
- BEST FOR SMALLER HOMES: EcoSmart ECO 11 Electric Tankless Water Heater
- MOST VERSATILE: Stiebel Eltron 240V DHC-E12 Single/Multi Water Heater
- BEST POINT OF USE UNIT: Ecotouch Tankless Water Heater
- ALSO CONSIDER: Rheem RTEX-18 240V Electric Tankless Water Heater
What to Consider When Choosing the Best Electric Tankless Water Heater
Shoppers looking to buy the best tankless water heater for their homes should know that the process of finding one involves more than just determining whether it will heat sufficient water. The type, flow rate, and other features play an important role, too. Here are several key issues that will likely influence decision-making.
Type
There are two main types of electric tankless water heaters: whole house or point of use (often referred to as POU or single point).
When considering replacing a traditional hot-water tank with an energy-saving electric tankless model, a whole-house solution is the most straightforward and doesn’t require additional plumbing. In new homes, or where guest accommodation has been added, point-of-use heaters might be the more economical answer. Although initial costs are a little higher, heating water close to where it’s needed means unused water doesn’t go cold sitting in long lengths of pipe, so less energy is wasted. However, there is no one-size-fits-all solution; each installation needs to be assessed individually.
Portability is a challenge because these devices are designed to be permanently wired—even for RV use. If a plug-in electric water heater is required, the best option is probably an electric mini-tank model.
Flow Rate (GPM)
How much hot water an electric tankless water heater can provide—or flow rate—is the most important factor to consider and is given in gallons per minute (GPM).
The total number of showers, tubs, sinks, and washing machines inside a house helps the homeowner determine the water heater size needed. A 1- or 2-bath home typically needs around 5 GPM, while a 3- or 4-bath home needs a 10 GPM unit.
Water supply temperature impacts GPM, meaning a model fitted in the southern U.S. would provide a higher GPM than one fitted in northern states. Also, the GPM of electric tankless water heaters is often secondary to power (given in kilowatts, or kW). This figure gives the energy used and the heat provided.
Manufacturers usually offer guidance on their heaters concerning different levels of hot-water consumption. It’s a good idea to consult a qualified plumber or heating professional for further advice.
Efficiency Rating
A benefit of tankless water heaters is efficiency. They only heat water when needed, so very little energy is wasted, lowering utility bills. Electric tankless water heaters are typically more efficient than gas ones; the challenge is finding accurate ratings.
Gas models usually quote a Uniform Energy Factor (UEF) rating, a standard established by the U.S. Department of Energy. Most manufacturers of electric models typically use the Energy Factor rating that preceded UEF, though, and this is no longer considered sufficiently accurate. There’s no suggestion that these are misleading, but given that each manufacturer might use different criteria for testing, this isn’t the most accurate way to compare models.
That said, a percentage efficiency is usually quoted instead. The efficiency of gas models ranges from 80 to 93 percent, while electric models are often 98 or 99 percent efficient. That’s good for the environment and for lowering household bills.
Installation and Maintenance
Electric tankless water heaters are considerably easier to install than gas models because no venting is required. The devices are more compact and can be positioned just about anywhere that electricity and water can be provided.
While small and point-of-use models often run from a 120-volt (V) supply, larger, more powerful models require 240V and usually two or three breakers. DIYers with a thorough understanding of household electrical systems can tackle the work themselves, with no specialty tools required. Otherwise, a professional should be sought.
While these devices are largely trouble-free, a small amount of annual maintenance will keep them operating at peak performance, extending their working life. Most models have a screen filter to stop particles of dirt from entering the heater. This should be checked often for obstruction and cleaned if necessary. The system also needs to be flushed occasionally to prevent the buildup of chemical deposits.
Additional Features
Physical size is seldom a challenge with electric tankless water heaters. Water pipes and electrical conduits are small in diameter, so units are generally very compact and surprisingly slender. That said, dimensions might be important when installing point-of-use models.
Most are extremely quiet and don’t have the firing noise associated with gas models. Some manufacturers claim their heaters are completely silent.
These devices typically have some form of digital display. However, the controls and information provided vary considerably. Basic models might just have up-and-down arrows to increase or reduce power and a readout of the actual temperature. Others can have preset temperatures held in memory, provide adjustable flow control to reduce power consumption, or monitor and report energy savings.
FAQs
Our guide aims to address all questions and concerns shoppers have when they’re looking to buy a new electric tankless water heater. Sometimes questions can still crop up. Here are answers to some of the most common questions shoppers ask about buying the best electric tankless water heater for their homes.
Q. How does a tankless water heater work?
Turning on a faucet or shower activates the tankless water heater’s flow sensor, allowing the user to make the water hotter. It deactivates once the tap is closed.
Q. Do electric tankless water heaters need to be vented?
No. Unlike similar gas models, there is no carbon monoxide byproduct. Generally speaking, that makes electric tankless water heaters considerably easier to install.
Q. Can you still shower if your water heater is leaking?
Yes, but immediate professional repair or unit replacement is recommended to avoid minor to severe water damage.
Q. What are the signs your hot water heater is going out?
Dirty water, particularly if there are rust particles in it, is a sure sign of internal damage. Inconsistent performance and lack of response to temperature input are other indicators.
Q. How do you flush an electric tankless water heater?
Turn off the water and electrical supply, remove the heater element, fill the internal chambers with white vinegar, and then flush. Manufacturers usually provide instructions specific to each model.
Q. How long do electric tankless water heaters last?
A use life of 20 years or more can be expected according to the U.S. Department of Energy.
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