Tankless Electric Water Heaters
Buying Guide

A review of the popular tankless electric water heaters that are sold in US and Canada. Find out about the benefits, advantages and compare the features. A review of Eemax, Bosch, Titan, Seisco, Tempra and other popular manufacturers.

One is common for all electric tankless hot water heaters; they use electricity to heat water, on demand and in continuous supply. These are wall-mounted, small and compact heating appliances that can be installed on the wall, under the sink, in the bathroom or kitchen. Another great advantage is that the standby heat loss, found in tank-type heaters, is completely eliminated. According to the manufacturers, tankless electric units save more energy than the tank-type and have lower installation costs.


Whole-house electric water heaters can easily replace a storage tank type models, providing more floor space. These are usually wall mounted and centrally located, providing hot water to more than one fixture.

Point-of-use water heaters are designed to provide hot water to one fixture and are installed either above or below it, under the sink. These are used for the distant sinks to avoid long runs of the plumbing, in cottages, apartments, garage, small offices and businesses.


  • Small and compact size

  • Longer life

  • Less prone to rusting, corrosion and water leaking

  • Cheaper than gas model

  • Easier to install as there is no venting required

  • Great flexibility allows installation on places where the gas model cannot go
  • Less components to service or maintain


  • Existing electric service might need an upgrade or full revision - which can be very costly
  • A unit has to be wired directly into the home's main electrical panel

  • Electricity is more expensive than gas

  • Might not be suitable for colder regions
  • Limited volume of available hot water

  • Cold water sandwich effects are frequent so your daily habits have to be modified

Top manufacturers

Best selling models

Stiebel Eltron

Stiebel Eltron is the German manufacturer of tankless electric water heaters, that offers models for for point-of-use service and whole-house water heating. Stiebel Tempra is the most popular unit and it can be used in both applications.

Stiebel Mini

stiebel mini tankless

Stiebel Eltron Mini series offers the smallest heaters for water heating and are available in the range from 1.8 kW to 5.7 kW, making them ideal for point-of-use applications, such as small dish-washing jobs, hand, and face-washing.

Due to its small and compact size of 7.5 x 6.5" they can fit almost anywhere, saving you a lot of space.

Stiebel DHC

stiebel dhc

DHC and DHC-E tankless can save up to 50% when compared to the conventional tank-type water heaters. These are equipped with the exclusive, rugged copper heating coil for long service and since it is controlled by a flow switch the heating element can never fail prematurely.

DHC and DHC-E utilize the scald-guard thermostat, which keeps the temperature of hot water within the safe limits and the hydraulic control to make the operation quiet. There are several models available with the power range from 2.5 kW to 9.6 KW.

The DHC-E models feature an advanced microprocessor control so when you set the temperature on the control knob it ensures that water temperature doesn't fluctuate. Three models are in the offer where the power output is in the range from 5.4 kW to 12 kW. Some models have the power output, selectable via a jumper.


stiebel eltron tempra

Tempra is the most advanced electrical tankless water heater from Stiebel Eltron. It utilizes the heavy-duty electronics, microprocessor and with its advanced flow control, it ensures that the temperature of hot water is constant no matter what the water flow is. Tempra Plus uses the digital display to show the temperature and error codes. Six models are available and due to the power range from 9 kW to 36 kW, Tempra can supply enough hot water for different home sizes.


bosch tronic 5000

Another German manufacturer, Bosch, after discontinued PowerStar, introduced the new series of tankless electric water heaters, Tronic.

Bosch Tronic 5000 models are the whole-house units that come with the efficiency of approximately 97%. The built-in electronic water flow sensor and the element modulation provide better comfort due to the reduced cold water sandwiches.

There are two models available; 17.25 kW and 26.85 kW with the maximum capacity of 4 gallons per minute, for supplying hot water to more than one fixture.

bosch tronic 3000

Point-of-use units are available as the Bosch Tronic 3000 and are designed with the efficiency of 99%. There are five models with the power range from 3.0 kW to 12 kW and maximum capacity of 1.8 GPM at 45 F rise.



Eemax manufacturer offers an extensive line of tankless electric water heaters for residential use, as the whole-house, single and multi-point, point-of-use with the low and high flow or as a booster for sanitation. A wide variety of Eemax models covers many applications; from apartments and homes with the single shower to the whole house with multiple showers, boosters, solar backup, and jet tubs.

The advanced technology found in Eemax electric tankless water heaters feature the high adjustable thermostats that turn the unit OFF when the set temperature has been reached and it keeps the temperature constant regardless of a number of fixtures being used. Thermostatic models, for example, heat the water immediately, then gradually reduce the power.

Whole-house models have the staged activation to apply the power to heat only water you need, and in combination with the microprocessor hot water will be delivered with the safe temperature.

The largest model provides up to 6 GPM of hot water which makes it ideal for up to three fixtures running at the same time.


titan scr2

Titan tankless electric water heaters are using the advanced technology for faster and accurate hot water production.
For example, Titan SCR2 uses the technology developed by this manufacturer and NASA. The SCR2 model incorporates the features that can manage the power output for the maximum efficiency and savings, also utilizes the shielded Incoloy heating elements which allow the use in any application, even where hard water is present.

SCR3 model utilizes very convenient and energy saving features such as the display of the real-time usage and efficiency and dual stage power control.

SCR4, with the power output of 21 kW and water flow of 5 gallons per minute, is the largest and most powerful model, designed for bigger homes with multiple showers and located in the colder regions, where is the higher temperature rise.



One of the greatest features found in Seisco tankless electric water heaters is its power-sharing distribution method that allows an even distribution of power to all heating elements, which eliminates the hot spots, mineral build-up, and early failure. The computer controlled power assures the precise temperature control for better comfort and energy use.

Other advantages include the leak detection that sounds alarm if there is a leak and dual low-level detectors that prevent dry firing.
There are two types of the Seisco heaters, smaller, two-chamber models with the power up to 14 kW for the point-of-use service and four-chamber, with the maximum power of 28 kW, used mostly as the whole-house units.


As seen from the above, small electric water heaters are heating water on demand either for one single sink/shower or multiple fixtures, and are the perfect supplement to an existing system, which cannot satisfy user requirements. These also work great in conjunction with the solar and geothermal WHS.

Tankless electric water heaters are perfect not only in residential homes, cottages, cabins, apartments but in commercial applications such as the: office buildings, stores, restaurants, schools, hotels, motels, factories...

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