The 5 Best Water Heaters for Hard Water to Enjoy Your Winter  

Since winter is coming, it would be required to warm yourself as well as, you may need hot water. To do this, you have to buy the best water heater for hard water. Now, it’s time to unwrap the 5 best water heaters for hard water.

Looking for the best geyser for hard water? Well, you are in your desired place. This article will illustrate the 5 best water heaters for hard water with features, specifications, pros, and cons. 

The influence of limescale formation in your water heater and other water appliances may be reduced only by the best water heater for hard water that is strong and long-lasting enough. You may relax knowing that this device will keep supplying your family with enough hot water no matter where you live.


Rinnai Tankless Water Heater

Bosch Electric Mini-Tank Water Heater


5 Best Water Heaters for Hard Water in 2022 to Get a High Level of Hygiene

How you will choose the best water heater for hard water for your home is currently the main concern. Let’s begin by taking a look at a few of the top water heaters on the market.

Products Best For Pricing Details 
Bosch Electric Mini-Tank Water HeaterSmall Spaces BUY NOW 
EcoSmart ECO 27 Electric Water HeaterLarge Homes BUY NOW
Stiebel Eltron Tankless Water HeaterWhole House BUY NOW
Rheem Tankless Electric Water HeaterLuxury Bathrooms & Vacation HomesBUY NOW
Rinnai Tankless Water HeaterMedium & Smaller Sized HomesBUY NOW

1. Bosch Electric Mini-Tank Water Heater

Bosch Electric Mini-Tank Water Heater
Bosch Electric Mini-Tank Water Heater

It can be annoying to have to wait for hot water at a sink that is far from the main heating source. It is just not practical to only have access to cold water from a sink and install hot water lines to each. 

A better option is to utilize the Bosch (ES2.5) Electric Mini-Tank Water Heater, a point-of-use electric mini-tank heater, to provide hot water where and when it’s needed. 

Most significantly, it can easily fit in a cabinet or underneath a sink or installed on the wall or floor-mounted. 

This water heater can be positioned in line with tankless water heaters to act as a buffer when there is intermittent cold water, a condition known as “cold water sandwiching,” or it can be used to augment an existing heater placed far from the sink. 


  • Brand: Bosch Thermotechnology
  • Capacity: 2.5 Gallons
  • Power Source: Corded Electric
  • Item Dimensions LxWxH: 13.75 x 10.75 x 13.75 inches
  • Color: White
  • Wattage: 1440 watts

Customer Reviews: 4.5 out of 5 stars (7,714 ratings)

Key Features

  • A 2.5-gallon point-of-use mini-tank that fits under your sink and serves as a convenient hot water heater provides hot water where you need it. 98% thermal efficiency. 13.75 inches wide by 13.75 inches high by 10.75 inches deep
  • Long-lasting quality: This electric water heater includes a quality glass-lined material for long service life and is simple to maintain. (Amps: 12A, Volts: 120VAC)
  • A separate installation: For independent installation or when connected to a sizable hot water source, the 36-37″ chord plugs into a 120-volt outlet.
  • Fast recovery rate: Get hot water on demand for all of your needs instead of having to wait for it to heat up at the sink (supplies up to 2 sinks at a time)
  • EASILY MOUNTED: The water heater can be installed right at the sink to give hot water, and it can be a shelf, wall, or floor-mounted (bracket included).


  • Suitable for small spaces 
  • Ensure quality for long life 
  • Provide 98% thermal efficiency


  • Short power cord
  • Modest recovery rate


2. EcoSmart ECO 27 Electric Water Heater

EcoSmart ECO 27 Electric Water Heater
EcoSmart ECO 27 Electric Water Heater

The EcoSmart ECO 27 is a 27 kW tankless electric water heater that is best suited for larger homes in warm climates and small whole-home applications with cooler input water temperatures as well as bigger residences in warm climates.

Depending on the temperature of the inflow water, it can deliver between 2.7 and 6.5 gallons per minute. Please refer to the sizing guide in order to choose the best option for your hot water requirements. 

You will be more content with EcoSmart because it allows you to use less water and energy while still providing you with the warm water you need whenever you need it.


  • Brand: EcoSmart
  • Capacity: 3 Gallons
  • Power Source: AC
  • Item Dimensions LxWxH: 3.75 x 17 x 17 inches
  • Color: White
  • Wattage: 27 KW
  • Voltage: 240 Volts

Customer Reviews: 4.5 out of 5 stars (4,598 ratings)

Key Features

  • Unlimited on-Demand Hot Water; Consistent, never-ending hot water when you need it; Efficiency and consistency are guaranteed within one degree of the chosen temperature thanks to continuously monitoring water temperature and controlled flow rates.
  • Saving space; EcoSmart tankless electric water heaters can be mounted on a wall or at the point of use and are 90% smaller than conventional tank heaters. 17 x 17 x 3.75 inches in size
  • Save energy; 99% thermal energy efficient EcoSmart tankless electric water heaters only heat water when it is needed, as opposed to tank heaters that keep the water at a constant temperature even when not in use. The Department of Energy claims that you can reduce your water heating expenses by up to 50%.
  • Refer to the sizing map for the EcoSmart ECO 27. Refer to the sizing guide to choose the right option. Requires 3×40 AMP Double Pole Breakers, a 27-kilowatt tankless electric water heater that is perfect for providing hot water for whole-home applications; it can produce between 2.7 and 6.5 gallons of water per minute depending on the temperature of the inlet water.
  • Limited lifetime warranty on the exchanger, element, and electronics; UL-499 certification; ETL listing.
  • Number of required breakers: three 40 Amp Double Pole
  • 200 Amps is the recommended electrical panel.
  • With an ECOSMART tankless water heater, you’ll never run out of hot water.
  • Up to 12 cubic feet of storage space can be saved.
  • Users have complete control over hot water thanks to digital temperature control with 1-degree increments.


  • Save energy, space, and time 
  • Provide resettable thermostat
  • Integrated with a copper heat exchanger
  • Almost 99.8% energy efficiency


  • Not suitable for residential homes
  • May not get a lifetime warranty


3. Stiebel Eltron Tankless Water Heater

Stiebel Eltron Tankless Water Heater
Stiebel Eltron Tankless Water Heater

Do you need a water heater for the entire house that can effectively handle hard water? The Stiebel Eltron Tempra 29 Plus Tankless Water Heater is a good option in that situation.

The innovative Advanced Flow Control German patented technology created by Stiebel Eltron is featured in the Tempra 29 Plus Tankless Water Heater to automatically control water temperature for continual comfort. 

To make sure that hot showers won’t ever be interrupted, it will gently restrict flow if hot water demand exceeds capacity. Tempra 29 Plus typically consumes between 15% and 20% less energy than traditional electric tank water heaters.


  • Brand: Stiebel Eltron
  • Capacity: 0.39 Gallons
  • Power Source: Hard Wiring Required
  • Item Dimensions LxWxH: 4.63 x 16.63 x 14.5 inches
  • Color: White
  • Wattage: 28.8 KW
  • Voltage: 240 Volts
  • Material: Copper

Customer Reviews: 4.6 out of 5 stars (1,456 ratings) 

Key Features

  • On-demand, a limitless supply of hot water is available.
  • A sleek design requires no ventilation and saves space.
  • 240 or 208-volt electric service must be hard-wired, with a maximum draw of 28,800 watts at 240 volts or 21,600 watts at 208 volts.
  • requires a minimum of 200 amps of total service to the home, 3 separate dedicated 40 amp breakers, and 8 gauge copper wiring.


  • Digital display system
  • Small and compact 
  • Silent operation 
  • Advanced flow control 


  • Difficult to install 
  • Little bit expensive 


4. Rheem Tankless Electric Water Heater

Rheem Tankless Electric Water Heater
Rheem Tankless Electric Water Heater

If you are looking for an appropriate water heater for houses with busy families, homes with luxurious bathrooms, and vacation homes, you can undoubtedly go for Rheem Tankless Electric Water Heater. 

In addition, the point-of-use electric models are perfect for a single faucet or shower as well. With a Rheem tankless water heater, you can take advantage of the comfort and convenience of continuous hot water on demand. 


  • Brand: Rheem
  • Power Source: AC/DC
  • Item Dimensions LxWxH: 18.5 x 14.5 x 3.5 inches
  • Color: Gray
  • Wattage: 18000 watts
  • Voltage: 240 Volts
  • Material: Stainless Steel

Customer Reviews: 4.4 out of 5 stars (1,185 ratings)

Key Features

  • Ensure the degree of accuracy of external digital thermostat control with LED display
  • newest self-modulation technology, adjusting power to supply hot water need
  • Durable Two heating elements made of copper that are field serviceable. The maximum flow rate of 4.4 GPM
  • Bottom 3/4 inch NPT water connectors for easy installation
  • Digital temperature display, threaded for easy replacement, and simple installation


  • Powerful performance 
  • Optimized operation 
  • Energy modulation 
  • Do not require venting 


  • Little bit heavy 
  • Difficult to install


5. Rinnai Tankless Water Heater

Rinnai Tankless Water Heater

For a home with mild to moderately hard water, Rinnai Tankless Water Heater will be ideal. It features a built-in scale detection mechanism that warns you when limescale production is beginning. 

Moreover, you may prevent calcium and magnesium from accumulating in the heat exchanger and heating elements of your appliance by taking preventative actions.

The high-efficiency non-condensing indoor tankless water heater models from Rinnai provide your house with cutting-edge technology that is both comfortable and affordable. At a constant pre-set temperature, you’ll get clean, dependable hot water while conserving energy and priceless floor space in your house. 


  • Brand: Rinnai
  • Power Source: Gas Powered
  • Item Dimensions LxWxH: 17.32 x 30.51 x 12.8 inches
  • Color: Indoor Installation
  • Voltage: 120 Volts
  • Item Weight: 45.6 Pounds
  • Style: Propane, Indoor Installation

Customer Reviews: 4.5 out of 5 stars (472 ratings)

Key Features

  • Original Design: To save energy, tankless hot water heaters only heat when necessary; Check out our new RE180iP model for the most recent in non-condensing technology and a cleaner layout that expedites service and installation.
  • With this Small Propane Water Heater, You’ll Never Run Out of Hot Water: The Rinnai 7.5 GPM non-condensing tankless hot water heater is only the size of a compact suitcase and fits in a range of places (5 fixtures at once)
  • Intelligent, robust design: Improved scale detection aids in avoiding serious, long-lasting unit damage; includes a heat exchanger, labor, and parts guarantee of 15 years, 5 years, and 1 year, respectively; For WiFi control, see the Control module (not included)
  • Recommended Professional Installation: To find a certified installer for your tankless water heater in your area, go to the Find a Rinnai PRO page on our website; Without a technician’s assistance, we do not advise installing a water heater.
  • Locate Your Rinnai To find the best tankless water heater for your home, check out our product guides, manuals, energy guide, warranty information, videos, and tables; To find out if this heater is the best choice for your area, view our map of groundwater temperatures.


  • WiFi connectivity
  • Easy to install 
  • High efficiency 
  • Integrated with an advanced scale detection system 


  • Not energy star qualified
  • Sometimes it takes longer to provide hot water 


How to Choose the Best Geyser for Hard Water? 

A higher Bureau of Energy Efficiency (BEE) star rating is preferred for geysers. A device with a 4 or 5-star rating is ideal because it will reduce energy consumption and lower your electricity cost. 

So, you should consider the following factors before buying any geyser for hard water.  

Family Size

The size of the geyser is another aspect where we frequently err when choosing the ideal geyser for salt water. What size of water heater is best for you depends on how many people are taking hot showers at peak times. 

Normally, 6, 10, and 15 liters should be plenty for a family of two to three individuals. 25 liters or more is advised for groups of four or more.

Energy Efficiency

The best electric geyser for hard water would have energy efficiency as one of its characteristics. 

According to the analysis of the U.S. Energy Information Administration

“Around 19% of energy has been consumed in all homes and 32% of energy has been consumed by apartments among them 17% of single-family detached and 19% of single-family attached.”

The geyser is more energy efficient the higher its BEE (Bureau of Energy Efficiency) star rating. So, it is very significant to think about energy efficiency to choose any geyser for hard water. 

I have already mentioned that you should ideally choose a device with a 4 or 5-star rating. It will assist to maximize energy usage and reduce your electricity bill. 

Weather Conditions

When choosing the best geyser for hard water, the weather should also be taken into account. Six to ten liters of tank storage are enough if the temperature is moderate, such as between 15 and 20 degrees.

Nevertheless, if you live somewhere really cold, 50 liters of capacity is advised. On the other hand, your skin may be getting rough and dull because of changing weather. To resolve these kinds of issues, you need to buy the best water humidifier for your living space.   

Tank Quality

This is another crucial factor to choose the best electric water heater for hard water. A tank with a glass liner is preferable to one with a metal liner. This will shield the geyser from corrosion in hard water situations, extending its lifespan. 

Additionally, you should purchase the geyser from a reputable company that provides at least a one-year warranty on the appliance and offers helpful post-purchase support.

However, the following aspect you are definitely thinking about, and these questions may come to your mind!

Which Water Heater Is Better for Hard Water?

When handling hard water, tankless water heaters perform better. Even if the buildup occurs, it happens more gradually than with traditional heaters.

Unlike conventional water heaters, tankless water heaters do not keep water in a tank, therefore they do not amass hardness minerals as quickly. Limescale gradually raises the heat exchanger’s temperature.

How Long Do Water Heaters Last?

The life expectancy of a water heater is between 8 and 12 years, which is based on the manufacturer’s recommended service life. 

That varies depending on the unit’s location and design, installation quality, maintenance schedule, and water quality. However, you can anticipate the water heater to endure for about a decade if you purchase it from a reputable manufacturer in the industry.

What Is the Most Reliable Brand of Hot Water Heater?

Making the right water heater choice for your house might be difficult. Since water heaters are not inexpensive and you will probably use the one you choose for many years to come.

  • Bosch
  • A.O. Smith
  • Stiebel Eltron
  • Rheem
  • EcoSmart
  • Rinnai
  • Kenmore
  • Bradford White
  • Navien
  • Reliance

What Are the Signs that Your Water Heater Is Going Out?

The temperature variations would be the first thing you would notice. You won’t get water at the temperature you’ve selected if your water heater is broken. Also, you may face the following indications. 

  • Unusual noise 
  • Water looks cloudy or rusty
  • Leakage issues 
  • Heating issue   


Pick the Best Water Heater for Hard Water & Enjoy Your Winter with Safety!

You have already observed the 5 best water heaters for hard water with details. Hopefully, you can choose your preferred one. However, if you have still confused, you can go for our recommendation.

We always prioritize customer satisfaction and we try to offer the best solution to our readers. If you take a glimpse at Google Trends, you can observe the demand and trends of some popular water heaters. 

So, you can undoubtedly try our recommendation, we guarantee that will ensure the best experience along with a high level of hygiene and safety. 

In this regard, you can take a look at the Rinnai Tankless Water Heater which will ensure quality treatment from anywhere and anytime. We have recommended it based on Google Trends and users’ interests.  

Rinnai Tankless Water Heater





Hopefully, you have got a detailed review to buy the best water heater for hard water. It is crucial to seek the distinct features that increase the water heater’s resistance to the creation of limescale.

You can upgrade your domestic plumbing system with a water softener or conditioner if you want to increase the ability of these elements to prevent limescale accumulation. The impact of hard water on your heater, pipes and other water appliances can best be remedied by doing this.

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