Choosing the Best Electric Tankless Water Heater

The Top 3 Best Electric Tankless Water Heater Options

Are you in the market for a new tankless water heater but not sure which one to choose? With so many options out there, it can be overwhelming to make a decision. That’s where we come in! In this blog post, we’ll be comparing three popular tankless water heaters: the top-of-the-line Stiebel Eltron Tempra 36 Plus, the EcoSmart ECO 27, as the middle-of-the-road option and the budget-friendly Rheem 240V Heating Chamber RTEX-13.

We’ll break down the features and specifications of each model to help you make an informed decision that fits both your needs and budget. So, whether you’re looking to save money or splurge on the best, read on to find out which of these tankless water heaters is the right choice for you.

Factors to Consider When Choosing an Electric Tankless Water Heater

If you are considering switching to an electric tankless water heater, it is important to understand the key factors to consider before making your purchase. Here are the top factors to keep in mind when choosing an electric tankless water heater:

  1. Water demand and flow rate: One of the primary factors to consider when selecting an electric tankless water heater is the amount of hot water you require. This will depend on the number of people in your household, the number of bathrooms and appliances that require hot water, and the flow rate of the fixtures. A high flow rate means that you will need a larger tankless water heater with a higher heating capacity.
  2. Temperature rise and incoming water temperature: Another important factor to consider is the temperature rise required for your household’s hot water needs. The temperature rise is the difference between the incoming water temperature and the desired hot water temperature. The colder the incoming water temperature, the higher the temperature rise required to reach the desired hot water temperature. This will impact the size and heating capacity of the electric tankless water heater you need.
  3. Sizing considerations: Choosing the right size electric tankless water heater is crucial to ensure that you have enough hot water for your needs. Sizing considerations include the size of your home, the number of people in your household, and the number of appliances and fixtures that require hot water. It is important to choose a tankless water heater that can meet your hot water demands without being over or undersized.
  4. Energy efficiency ratings: Electric tankless water heaters are known for their energy efficiency, but some models are more efficient than others. When selecting an electric tankless water heater, it is important to consider the unit’s energy efficiency rating. Look for models with high energy efficiency ratings, such as Energy Star certified models, to ensure that you are getting the most energy-efficient option available.
  5. Cost considerations: Finally, cost is always a consideration when purchasing any appliance or household item. Electric tankless water heaters can be more expensive than traditional tank-style water heaters, but they can save you money in the long run by being more energy-efficient. It is important to consider the upfront cost of the unit, as well as any installation and maintenance costs, to ensure that you are getting a cost-effective option for your household’s needs.

By keeping these key factors in mind, you can select the best electric tankless water heater for your household’s hot water needs.

Rheem 240V Heating Chamber RTEX-13
Rheem 240V Heating Chamber RTEX-13

Frequently Asked Questions about Electric Tankless Water Heaters

If you’re considering the purchase of an electric tankless water heater, you may have an abundance of inquiries regarding their functionality, benefits, and how to select the appropriate one for your household. Presented below are some of the most common questions about electric tankless water heaters:

How do electric tankless water heaters operate?
Electric tankless water heaters function by immediately heating water as it passes through the system. Once cold water enters the heater, it gets heated by either an electric element or gas burner and then exits the unit as hot water.

What are the advantages of electric tankless water heaters?
Electric tankless water heaters are more energy-efficient compared to conventional tank-style water heaters, meaning that they can significantly reduce your energy expenses. They provide hot water on demand, meaning that you will never run out of hot water. They also require less space, and have a lengthier lifespan.

How do I choose the appropriate size of an electric tankless water heater for my home?
Choosing the suitable electric tankless water heater size is dependent on various factors, including your household’s size, number of occupants, and the number of appliances and fixtures that necessitate hot water. It is advisable to consult the manufacturer’s sizing chart or seek assistance from a licensed plumber to determine the appropriate size for your home.

Can an electric tankless water heater provide sufficient hot water for my entire household?
Yes, electric tankless water heaters are capable of supplying sufficient hot water for the whole household. However, it is essential to select a model with a high flow rate and heating capacity that meets your household’s hot water requirements.

Are electric tankless water heaters more expensive than conventional tank-style water heaters?
Electric tankless water heaters may have a higher upfront cost than conventional tank-style water heaters. Nonetheless, they can save you more money in the long term by being more energy-efficient and having a longer lifespan.

How do I install an electric tankless water heater?
A licensed plumber or electrician can install an electric tankless water heater. Appropriate electrical wiring and ventilation, if applicable, are necessary for installation.

What maintenance do electric tankless water heaters require?
Electric tankless water heaters require minimal maintenance. It is advisable to flush the unit yearly to remove any mineral accumulation and replace the air filter if needed.

The EcoSmart ECO 27 Electric Tankless Water Heater

The EcoSmart ECO 27 Electric Tankless Water Heater stands at an 8.7/10 rating with the best warranty among other electric water heaters on the list. It is the latest model in the ECO series of EcoSmart’s popular range of electric tankless water heaters.

In areas with ample sunlight, the ECO 27 electric tankless water heater can provide a constant supply of hot water at 6.6 GPM to a single-family house. This capacity is more than enough to accommodate two showers and an extra fixture, which emits around 2 GPM. Its suitability makes it an ideal choice for apartments, and townhouses. It can heat nearly 3 gallons of water per minute, even at the lowest groundwater temperatures. This is sufficient for two showers that emit no more than 1.5 GPM each in the northern regions of the United States.

The Ecosmart Eco 27 electric tankless water heater is equipped with an energy-efficient self-modulating heat sensor that keeps it operating at an optimal energy level. If there is a high demand for water, most electric tankless water heaters would provide less hot water because they cannot keep up. The Ecosmart Eco 27, on the other hand, regulates water flow to ensure that the temperature remains ideal.

This electric tankless water heater comes with a comprehensive list of features, including:

A constant supply of hot water that never runs out. The monitored water temperature and regulated flow rates ensure consistent performance within one degree of the specified temperature.
Stainless steel and copper components are used to increase longevity and efficiency.
It has a flow rate of 6.6 GPM at an inlet temperature of 74°F. This is sufficient to supply hot water to four fixtures in your home.
The ECO 27 is small enough to fit into the tightest spaces within the house, measuring 17″ x 17″ x 3.75″. It is an excellent option for condominiums and apartments.
Self-modulating technology automatically adjusts the flow rate to keep up with demand.

The ECO 27 has a power output of 27kW, which is divided into three 9kW heating chambers. This allows the water heater to consume only the amount of energy required to heat the water. According to EcoSmart, its water heaters can reduce your water heating costs by up to 50% due to this technology.
The EcoSmart ECO 27’s heat exchangers, electrical components, and heating elements are covered by an exceptional limited lifetime warranty. No other manufacturer on this list offers this type of warranty.
At the price, the ECO 27 is one of the most affordable electric tankless water heaters on the market.

During my evaluation of the EcoSmart ECO27 electric tankless water heater, I discovered a few flaws. Despite the manufacturer’s assurances of the copper components’ longevity, there have been several instances of heaters malfunctioning due to severe corrosion of the copper elements.

One more thing to keep in mind, and it’s very important. The lifetime warranty is only valid if the water heater is installed by a licensed plumber, that is the first thing. Secondly it needs to be registered within 30 days of purchase on the manufacturer’s website. The customer support is also not as responsive as I expected, with reports of customers being left on the line for hours and others complaining about long-winded arguments with support staff.

Overall, if you require an electric tankless water heater for your entire home, the EcoSmart ECO 27 is energy-efficient and equipped with a simple digital thermostat for accurate temperature control. It can serve a single-family household and comes in a compact package, making it perfect for individuals with limited space. Additionally, the warranty is exceptional, as long as you have a professional install the EcoSmart ECO

EcoSmart ECO 27 Tankless Water Heater, Electric, 27-kW – Quantity 1, 17 x 17 x 3.5
  • 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 3×40 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

The Stiebel Eltron Tempra 36 Plus

The Stiebel Eltron Tempra 36 Plus is the best electric tankless water heater, according to my review, scoring 9 out of 10. This German-made Tempra series is small but powerful enough to supply hot water to multiple fixtures and locations in any season or environment.

The Tempra 36 Plus is the most advanced model, offering the highest quality and most excellent value. Unlike other electric tankless water heaters, this unit’s heating elements will never need to be changed thanks to a secondary thermal cut-out switch. This not too cheap tankless electric water heater is designed to last, with solid copper heat exchangers and brass fittings.

This water heater offers an endless and uninterrupted supply of hot water as needed. Its elegant design saves space and doesn’t require any ventilation. The electronic switch is activated for a silent operation, and it operates on a single 60 Hz phase, with a voltage of 208 V and a wattage of 27 kW. The copper-sheathed heating element is housed in a copper cylinder, ensuring its durability. Additionally, it comes with a seven-year warranty against leakage and a three-year warranty for parts, ensuring your peace of mind.

One reason I chose the Tempra 36 Plus as the best is its patented Advanced Flow Technology. To prevent the water heater from being overworked, Advanced Flow Control automatically adjusts the cold water flow rate. The Tempra 36 Plus ensures the specified hot water temperature is maintained, as opposed to water heaters from other manufacturers that may provide water that is too cold to be used.

Some other features of this electric water heater include self-modulating technology that gauges the temperature of the incoming water and adjusts the heater accordingly, and a digital thermostat that precisely regulates the temperature. It also allows for user customization and displays useful information such as water flow, wattage, fault codes, energy-saving data, and more.

Smart microprocessor technology and several temperature and water-flow sensors work together to regulate water flow and temperature. The operation is silent, with no moving mechanical components. The Tempra 36 Plus can provide hot water to up to four fixtures simultaneously, with a maximum flow rate of 8 GPM (gallons per minute).

Additionally, the Tempra 36 Plus is compact and takes up minimal space. There is a seven-year warranty against leakage and a three-year warranty against workmanship and material defects. However, there are a few drawbacks. This Stiebel tankless water heater needs a 3×60 amp circuit breaker, which takes up substantial panel space. Also, some customers have claimed that the “cold-water sandwich” effect is still present, particularly when two fixtures are in use simultaneously.

If we are being picky it’s not cheap to buy.

In conclusion, the Stiebel Eltron Tempra 36 Plus Tankless Electric Water Heater offers the best value at a reasonable price. Its sleek and compact design enables it to fit into small spaces around the house, making it an excellent energy-efficient option for low-flow applications. It also has sophisticated control systems that enable users to monitor and modify the temperature and water flow easily.

Stiebel Eltron Tankless Heater – Tempra 36 Plus – Electric, On Demand Hot Water, Eco, White
  • On-demand, continuous and unlimited supply of hot water
  • Sleek design saves space and no venting required
  • Electronic switch activated for virtually silent operation. Phase- single 60 Hz. Voltage- 208 V. Wattage- 27 kW
  • Copper sheathed heating element housed in copper cylinder
  • 7 Years leakage and 3 years parts complete warranty

Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater

This is the more affordable option.

The Rheem RTEX 13 is a newly added electric tankless water heater to the Rheem series, and it is considered to be one of the most cost-effective electric tankless water heaters available in the market. It is mainly designed for point-of-use applications, such as single-shower installations, and can deliver a maximum hot water output of four gallons per minute. The RTEX 13 comes equipped with a front-mounted adjustment dial that allows you to change the water temperature as per your requirements. Additionally, there is a digital temperature control present on the front panel of the heater that indicates whether the device is active or in standby mode.

One of the significant benefits of this electric tankless water heater is its efficiency in conserving energy. The RTEX 13 boasts a staggering 99.8% energy efficiency, rendering it an optimal option for those seeking to curtail their yearly power expenses. The RTEX 13 has a power rating of 13 kW and requires a 60A/240V circuit breaker and 6 AWG wire. Utilizing this water heater in conjunction with a running faucet can result in significant long-term power savings.

The RTEX 13 comes packed with several features, such as providing an on-demand steady flow of hot water, allowing precise temperature regulation in increments of 1° from 80 to 140 degrees Fahrenheit, having sturdy copper immersion heating components with a threaded brass top for quick repair and increased durability, a maximum flow rate of 4.8 GPM, and requiring a minimum water flow of 0.4 GPM to activate. At a price of around $280, the RTEX 13 is an affordable option compared to other electric tankless water heaters on the market. It also comes with a five-year heating chamber and a one-year parts limited warranty.

However, Rheem markets the RTEX 13 as a whole-house solution for heating water, which may not be entirely accurate. This tankless water heater is suitable for single-use or POU applications and is incapable of supplying hot water to three fixtures simultaneously, particularly in colder areas. You may need to upgrade to larger and more expensive models in the RTEX series. Additionally, the copper elements in the heater require frequent maintenance or replacement to increase its longevity.

In conclusion, the Rheem RTEX 13 electric tankless water heater appears to be a reliable and cost-effective option for individuals looking for a point-of-use solution. It may not be suitable for colder areas due to its capacity limitations and flow rate variables, but quality control challenges can be mitigated with extra care. If installed by a certified expert and used according to the manufacturer’s instructions, the RTEX 13 can be a wise investment..

Rheem 240V Heating Chamber RTEX-13 Residential Tankless Water Heater, GRAY
  • External adjustable digital thermostatic control with LED display (+/1 degree accuracy
  • Durable Copper immersion two heating elements, field Serviceable.Self-modulating power control
  • Simple installation – 1/2 NPT adapters included; side 1/2 inch Compression water connections
  • 99.8% energy efficient. External controls to adjust temperature in increments of 1°f. Water-Saver Shower Head – 1.5 GPM
  • Threaded for easy replacement, simple installation, digital temperature display 54 A. 13kW Model Flow Rate: up to 3.17 GPM