Top 7 Best Tankless Water Heaters for Hard Water – Reviews & Buying Guide

Hard water can be a real challenge when it comes to selecting the right tankless water heater. The minerals present in hard water can cause limescale buildup, reduce efficiency, and even damage conventional water heaters. 

That’s why it’s crucial to choose a tankless water heater specifically designed to handle hard water conditions. In this comprehensive guide, we’ll review the top 7 tankless water heaters for hard water and provide you with all the information you need to make an informed buying decision.

Top 7  Best Tankless Water Heaters for Hard Water – Reviews

The Rinnai RL Series RL75iN is the ultimate tankless water heater for hard water areas. Its compact and durable design allows for easy installation in indoor locations, providing reliable hot water on demand. 

With a flow rate of up to 7.5 gallons per minute, it can meet the hot water demands of multiple fixtures simultaneously, ensuring an uninterrupted supply throughout your home. Operating the RL75iN is a breeze thanks to its user-friendly interface and intuitive controls, and the straightforward installation process comes with all necessary accessories. This tankless water heater is specifically designed to combat hard water conditions, effectively addressing limescale buildup and minimizing maintenance requirements. With a remarkable UEF of 0.81, it is highly energy-efficient, leading to significant savings on utility bills while reducing your carbon footprint. Although it lacks Energy Star certification, its impressive efficiency rating speaks volumes. 

Say goodbye to hard water woes and embrace the exceptional performance and innovation of the Rinnai RL Series RL75iN.

The Rheem RTGH Series is a top-tier condensing tankless gas water heater. Its durable construction and stainless steel condensing heat exchanger make it an excellent choice for areas with hard water, as it resists corrosion and enhances heat transfer efficiency. 

With a flow rate of up to 9.5 gallons per minute, it meets the hot water demands of multiple fixtures simultaneously, ensuring a continuous supply of hot water throughout the house. Setting up and operating the RTGH Series is hassle-free, thanks to its user-friendly interface and intuitive controls. 

It comes with a 2″ venting system for easy installation and may offer additional accessories for enhanced usability. The RTGH Series is highly energy-efficient, with a UEF rating of up to .93, helping reduce utility bills and carbon footprint. Its advanced technologies effectively handle limescale buildup, ensuring optimal performance and minimizing maintenance requirements.

Installation is straightforward, and maintenance procedures are relatively simple, ensuring long-term performance. Choose the Rheem RTGH Series for a reliable and efficient solution to tackle hard water challenges.

The Rinnai RU Series is another dependable gas-fired tankless water heater that’s perfect for hard-well water. Its compact design and durable construction make it suitable for indoor installation. With a flow rate of up to 7 GPM, it can deliver hot water to multiple fixtures simultaneously, ensuring a constant supply. 

The user-friendly interface and intuitive controls make it easy to operate, and the installation process is straightforward. The RU Series is energy-efficient, with an impressive energy factor of up to 0.95 to 0.96, helping homeowners save on utility bills. 

It is also ENERGY STAR® certified. The unit’s advanced technologies effectively handle hard water conditions, minimizing limescale buildup and reducing maintenance requirements. Installation is hassle-free, and most homeowners can handle it themselves. Regular maintenance is relatively simple, ensuring long-term performance.

At number four on our list comes the EcoSmart ECO 36kW. Known for its efficiency and affordability, it goes well for hard water conditions. It features a sturdy construction and durable materials, ensuring long-lasting performance. With a flow rate ranging from 3.6 to 8.7 gallons per minute, it meets the hot water demands of multiple fixtures simultaneously. 

The unit is user-friendly, with intuitive controls and easy temperature adjustments. Its compact design allows for easy installation, and DIY installation is possible for most homeowners. The ECO 36kW is energy-efficient, thanks to its patented self-modulating technology that optimizes energy consumption based on demand. It effectively handles hard water conditions, addressing limescale buildup and ensuring consistent performance. The unit’s design and materials contribute to its resistance against the effects of hard water, ensuring longevity and high performance. 

Overall, the EcoSmart ECO 36kW is an ideal choice for those seeking an affordable and reliable tankless water heater for hard water conditions.

Check out our top tankless water heater recommendations for large homes.

The Eemax EEM24013 is a compact and efficient point-of-use tankless water heater sitting at the 5th position in this review. Its durable construction, including stainless steel materials, ensures long-lasting performance. With a power output of 13 kW and an operating voltage of 240 volts, it delivers instant and endless hot water, meeting the demands of multiple fixtures simultaneously. 

The unit incorporates advanced technologies to combat limescale build-up and protect against the effects of hard water. Installation is simple with the included electric cable and water connectors, and the user-friendly interface and controls enhance ease of use. 

While specific energy efficiency data is not available, tankless water heaters are known for their energy-saving capabilities, providing utility bill savings by eliminating standby heating. 

Overall, the Eemax EEM24013 excels in performance, efficiency, and durability, making it an ideal choice for households dealing with hard water challenges.

The Stiebel Eltron Tempra Plus 29 is a top-of-the-line whole-house tankless water heater known for its exceptional performance and ability to provide continuous hot water. Its modern design and high-quality construction make it durable and suitable for areas with hard water.

With a powerful output of 28.8 kW, it delivers a high flow of hot water, meeting the demands of multiple fixtures simultaneously. The advanced flow control function ensures a consistent output temperature, regardless of varying flow rates, while the self-modulation feature optimizes energy usage for impressive efficiency and reduced utility bills. 

The unit is user-friendly, with easy-to-use controls and a straightforward installation process that doesn’t require seismic building codes. Its self-cleaning capabilities and resistance to hard water effects minimize maintenance needs. 

The Tempra Plus 29 is well equipped to solve your hard water problem, incorporating technologies to combat limescale build-up and ensuring optimal performance and a longer lifespan. 

With its durability, efficiency, and hard water handling capabilities, it is the ideal choice for homeowners seeking a reliable and efficient hot water solution.

The Rheem RTEX-24kW is a top-notch tankless electric water heater designed for small families and excels in handling hard water. It features durable construction with high-quality materials and a compact design for easy installation in limited spaces. 

With a powerful 24kW output and a flow rate of up to 5.9 gallons per minute, it provides a reliable flow of hot water for multiple fixtures simultaneously. The self-modulating power control optimizes energy usage, resulting in exceptional energy efficiency and reduced utility bills. 

The user-friendly interface with adjustable digital temperature control ensures effortless temperature adjustments. The unit does not require venting, allowing for flexible placement options. It effectively handles hard water conditions with advanced technology that addresses limescale build-up and provides protection against the adverse effects of hard water. Professional installation is recommended, and regular maintenance, including flushing the supply line, ensures hassle-free operation. 

Overall, the Rheem RTEX-24kW is a reliable and convenient choice for continuous hot water supply, particularly in areas with hard water.

Buying Guide for Tankless Water Heaters for Hard Water

If you’re dealing with hard water, you understand the challenges of limescale build-up and its impact on appliances. When it comes to tankless water heaters, selecting the right one for hard water conditions is crucial. In this guide, we’ll cover considerations, specific features to look for, budget factors, installation and maintenance tips, and address frequently asked questions to help you make an informed decision.

Considerations for Hard Water Areas

When choosing a tankless water heater for hard water, prioritize units specifically designed to handle these conditions. Look for models with advanced technologies that combat limescale build-up and protect against the adverse effects of hard water. Additionally, consider the durability and materials used in the unit, as they contribute to its performance and lifespan. Steel is the best material for hard water.

Impact of Hard Water on Tankless Water Heaters

Hard water can cause significant problems for tankless water heaters if they aren’t equipped to handle it. Limescale build-up can clog pipes, reduce heating efficiency, and damage the unit over time. It’s vital to choose a tankless water heater designed to effectively handle hard water, ensuring optimal performance and extending its lifespan.

Specific Features to Look for in Models Designed for Hard Water

When evaluating tankless water heaters for hard water, focus on features that address the challenges posed by limescale. Seek units with advanced technologies like self-cleaning mechanisms or scale control systems. These features actively prevent limescale build-up, promoting efficiency and longevity in the presence of hard water.

Flow Rate and Capacity

In hard water areas, it’s important to consider the flow rate and capacity of the tankless water heater. Hard water can reduce the flow rate due to mineral buildup, so choosing a unit with a higher flow rate is recommended. Determine your household’s hot water demands and select a tankless water heater that can meet those needs even in hard water conditions.

Budget Considerations

Price is an important factor in any purchase. Tankless water heaters come in various price ranges, so consider your budget. While models with advanced features and enhanced hard water protection may have higher initial costs, assess the long-term savings they offer. Factor in potential energy bill savings and the extended lifespan of the unit, which can outweigh the upfront investment.

Remember, choosing a tankless water heater designed for hard water ensures optimal performance, durability, and savings in the long run.

Frequently Asked Questions

1. Can a regular tankless water heater be used in hard water areas?

Yes, but it’s highly recommended to choose a tankless water heater specifically designed for hard water conditions. These models have features that combat limescale build-up and protect against the adverse effects of hard water.

2. How often should I descale a tankless water heater in hard water areas?

The frequency of descaling depends on the hardness of your water and the manufacturer’s recommendations. It’s generally advised to descale the unit once a year or as specified by the manufacturer.

3. Are tankless water heaters for hard water more expensive than regular models?

Tankless water heaters designed for hard water may have a slightly higher price tag due to their advanced features and technology. However, considering the long-term savings and improved durability, they are a worthwhile investment.

4. What is the average lifespan of a tankless water heater in hard water conditions?

The lifespan of a tankless water heater can vary depending on various factors, including water hardness, usage, maintenance, and the quality of the unit. On average, a well-maintained tankless water heater can last 15 to 20 years or more in hard water conditions.

5. Can I install a tankless water heater for hard water myself, or should I hire a professional?

While it is possible to install a tankless water heater yourself, it is recommended to hire a professional for proper installation. They have the necessary expertise to ensure a safe and efficient setup. Besides, some brands require professional installation for warranty coverage.

Over to you!

Choosing the right tankless water heater for hard water areas is essential to ensure optimal performance, durability, and longevity. Consider the specific features designed to combat limescale build-up, evaluate your budget and potential long-term savings, and prioritize professional installation and regular maintenance. By following this buying guide, you can confidently select a tankless water heater that will effectively handle hard water conditions and provide you with a continuous supply of hot water for years to come.