The Best Tankless Water Heater For Hard Water In 2023

Summary
1. Best Overall: Rinnai V65iP Non-Condensing Propane Tankless Water Heater
With the Rinnai V65iP Non-Condensing Propane Tankless Water Heater, you will never run out of hot water. This propane tankless water heater is a smart, durable design that can be installed by professionals or do-it-yourselfers. With its professional installation recommended label and original design, you can be sure that the unit you are buying is designed for the best results. Read Review
2. Runner Up: Stiebel Eltron 239223 Tankless Water Heater
A hot water tankless heater which boasts a minimum of 200 total service to the residence, unlimited supply of hot water, and no venting required. This sleek design saves space and is a perfect addition for any home or business. Read Review
3. Best Safety: ECOTOUCH Tankless Water Heater
ECOTOUCH Tankless Water Heater is a new era in the development of water heating technology. With instant and sufficient hot water, with safe and durable performance and with an upgraded heating system to provide the perfect temperature for you. The ECOTOUCH Tankless Water Heater is also smart self-modulation which can automatically adjust the temperature according to your demand. Read Review
4. Lightest: FORUEE Tankless Water Heater Propane
Fully equipped with 5 safety protections, the FORUEE Tankless Water Heater is an instant hot water solution for any application. Rapidly generating heat from propane, the FORUEE will provide instant and continuous hot water to your home. It's lightweight design allows for easy installation in any space, and the LED display will let you easily adjust the temperature to meet your need. Read Review
5. Best Durable: ECOTOUCH Electric Tankless Water Heater 18kW, 240V
ECOTOUCH Electric Tankless Water Heater is a safe and durable, convenient to use and sufficient water heater. Features include instant hot water as well as self-modulation instant water heater that provides a constant temperature with just one touch of the button. The ECOTOUCH also ensures you have plenty of hot water even in cold weather. Read Review
Hard water is abundant in many places around the world, which means that it’s also abundant in your home. There are a number of reasons for this, but the most significant one by far is the presence of hard water. Hard water contains high amounts of minerals such as calcium and magnesium that cause scale to build up on pipes and fixtures, which then needs to be cleaned repeatedly with soap and water.
If you have hard water at home, you should look into getting a tankless water heater installed to take advantage of its other advantages over traditional storage tanks. A tankless system can heat up only as much water as you need at any given time, which makes them ideal for use in situations where you don’t want to run the risk of running out of hot water unexpectedly.
After doing extensive study and analysis over a considerable time, We think the best tankless water heater for hard water is Rinnai V65iP Non-Condensing Propane Tankless Water Heater. Other options presented here are certainly worthy of your attention, and in order to assist you in making an informed choice, We have compiled the following helpful buying guide.
Our Top Picks

Never Run Out of Hot Water with this Compact Propane Water Heater: Non-condensing tankless hot water heater from Rinnai is only the size of a small suitcase and fits in a wide variety of spaces, but provides up to 6.5 GPM (5 fixtures at once)
Smart, Durable Design: Enhanced scale detection helps prevent serious, long-term damage to unit; Includes 15-, 5-, and 1-year residential guarantee for heat exchanger, labor, and parts, respectively; See Controlr module for WiFi control (not included)
Find Your Rinnai: See our product guides, manuals, energy guide, warranty information, videos, and tables to find the right tankless water heater for your home; Check our Ground Water Temperature Map to see if this heater is optimal for your region
Professional Installation Recommended: Visit the Find a Rinnai PRO page on our website to locate a qualified technician in your area to install your tankless water heater; We do not recommend installing a water heater without a technician
Original Design: Tankless hot water heater only heats when necessary to conserve energy; For the latest in non-condensing technology and a cleaner layout that speeds up service and installation, check out our new RE160iP model

Requires 3 separate dedicated 40 amp breakers with 8 gauge copper wiring, and a minimum of 200 amp total service to the residence
On demand a continuous and unlimited supply of hot water
Sleek design saves space and no venting required
Requires hard-wired 240 or 208-volt electric service, with a maximum draw of 28,800 watts at 240 volts or 21,600 watts at 208 volts
【INSTANT & SUFFICIENT HOT WATER】Applied with 9kW heating system, the electric tankless water heater ECO90B supplies instant & endless hot water of 116℉or higher temp, no waiting for preheat nor temperature fluctuations, perfect companion for sinks, bringing you perfect experience of comfort and relaxing.
【SAFE AND DURABLE】Applied with multiple protection devices, every piece ECO90B tankless water heater goes through strict tests to ensure 100% safety. Inner water and electricity lines are designed to run separately so as to avoid leakage or harm of scale build up. Approval by ETL and qualifies for UL, you can expect outstanding performance for years to come.
【CONVENIENT USE】The ECO90B electric tankless water heater comes with digital display & touch control panel so temp setting is an easy job. It's space saving, measuring: 15.4″(H) x 10.3″(W) x 2″(D). Plus it has a stylish, modern design that blends in any decor. Please verify it is the right size for you: 9kW@240V; pipes fittings: 1/2" NPT.
【UPGRADED HEATING SYSTEM】Featuring micro-computer control and patent heating technology, ECO90B electric water heater promises no “cold water sandwiching”. And unique heating element avoids any corrosion inside pipes so as to extend service lifespan.
【SMART SELF MODULATION】The on demand electric water heater ECO90B adjusts power input based on flow rate and temp setting in real time. As water flow reduces, power input decreases, thus you still get ideal, comfortable temp instead of scalding hot water. Optimal energy efficiency 99.8% saves considerable electricity charge per year.
【LIGHTWEIGHT & INSTANT HOT WATER】 Only weighing 9 lbs and energy-saving, this portable propane water heater is perfect companion for your journey. With maximum power output 34,000 BTU/HR, you can get 1.32 gallons endless hot water easily wherever you are. No need to preheat before operating the propane hot water heater. As soon as you turn on the tap, you will get water at the temperature you desire.
【100% SATISFACTION】 This on demand propane water heater is the real deal! We aim to ensure that every customer have a happy and worry-free purchase experience. If you have further query please feel free to contact us.
【FULLY EQUIPPED】 No need to look around for accessories! This portable tankless water heater comes with a CSA gas regulator, a high pressure shower head with a 5-foot(1.5 meters) stainless steel hose, an US universal gas connector(fitted already), 2 garden hose adapters, wrenches and fitting kits.
【5 SAFETY PROTECTIONS】 Designed with oxygen depletion safety shut-off protection, over-heating protection, anti- freezing protection(a drain plug to discharge residual water), flame failure device and dry combustion protection, the camping propane water heater aims to keep you and your family safe all the time.
【EASY TO INSTALL & USE】 Started with 2.5 PSI low water pressure, this tankless water heater propane is good for RV camping, outdoor trip and washing pets. No electricity required, ignition of the propane water heater is with 2 pieces D cell batteries(not included). With the LED display, you can easily adjust the temperature to meet your need.

【SAFE and DURABLE】Newly updated and applied with multiple protections, such as leakage protection, over heating protection and auto stop. Every piece electric tankless water heater ECO180B goes through strict tests to ensure 100% safety and it is listed by ETL and qualifies for UL. Inner water and electricity lines are designed to run separately so as to avoid leakage risk and scale build up. You can expect outstanding performance for years to come.
【CONVENIENT USE】The electric tankless water heater 18kW comes with digital display & touch control panel so temp setting is easy job. Best of all, useful information on the screen helps you get full understanding of the working status of the 240v water heater tankless, you needn’t go through hard lesson of temp setting. Now turn on the faucet and let the smart instant hot water heater do the rest.
【INSTANT & SUFFICIENT HOT WATER】 With real powerful 18kW smart heating system, the tankless hot water heater electric ECO180B supplies sufficient instant and endless hot water of 120℉ or higher in seconds, no waiting for preheating nor terrible temp fluctuation during shower time any more and no worry of running out of it. Perfect companion for whole house use, including shower, sink faucets, dishwasher, washing machine, etc.
【SELF MODULATION INSTANT WATER HEATER】The electric on demand tankless hot water heater ECO180B adjusts exact power input based on current flowrate and temp setting. For example, less power will be consumed by the smart water heater when you reduce water flow, thus, you get ideal temperature instead of scalding hot, which ensures comfortable experience and excellent energy efficiency. Also, optimal energy efficiency of 98% saves considerable electric charge for you.
【POINT of USE WATER HEATER】The sleek tankless water heater ECO180B is compact as shoes box, making it possible to install anywhere point of use to avoid waste, ideal for shower, kitchen, bar, school and hair salon. Please verify it is the right size for you: 18kW at 240V(only); dimensions 12.22" (W) x 17.25" (H) x 4.02" (D); plumbing connections :3/4" NPT. In order to install 18kW Tankless Water Heater it would requires 240V, 2X40AMP Double Pole Breaker and 2X8AWG/2 wires with Grounding.

The tankless design means you don't have to wait 30 minutes for preheating and unlimited use of hot water.
Using built in forced exhaust fan at the bottom ensures stable combustion and eliminates the influence of external wind. Compact design for easy installation.
Fogatti provide free replacement within 30 days, and 5 years warranty on heat exchanger and 2 years warranty on other parts. The above-mentioned labor costs extra from 31 days.
We recommend that all installations of units must be done in accordance with the local building and plumbing codes of the installation location and installation be done by a licensed professional.
Excellent quality CSA certified in the United States and Canada. Adopting the world's most advanced technology, superior safety and durability.
145,000 BTU high heating capacity and maximum 6.3 GPM. It is suitable for 2-3 outlet points, which can satisfy whole family. UEF over 0.82, the high energy conversion rate can effectively reduce energy loss.

[Instant Unlimited Hot Water] - REQUIRE 3 SET x Double-pole 40AMP Breakers to Achieve 240V for this On demand tankless electric water heater, providing hot water in 3 seconds when you need it and as long as you need, eliminating wait time, never run out of hot water again and No More cold shower. Flow Rate 5.27GPM @35°F Rise
[Easy Installation & Safety Protection] - ETL certified with overheating protection, auto stop heating when detecting no water, quality workmanship for leakage protection
NOTE - Make sure this water heater is the correct size for your hot water need: 27kW at 240V draw max 114Amp; Required breaker 3 x Double-POLE 40AMP; Wire gauge 3 x 8AWG; Unit size 17.12" x 13.12" x 3.12"; Water connection 3/4" NPT. 2-year limite warranty and 24/7 customer support services.
[Self-modulating Power] - Self-modulating technology regulating the amount of energy required to heat water only when you need it with 99.8% efficient, saving up to 60% on water heating cost comparing to traditional tank water heater. Wall mounted compact size with no water tank, convenient for any spaces, saving floor space and fitting into tight spaces.
[Stable Water Temperature] - Auto adjusting energy consumption basing on income water temperature and flow, ensuring maximum efficiency, continuous stable temperature and optimal power usage. Digital temperature display allowing adjustment in 1° increment from 80°F to 140°F. Heating element separated from water tube significantly reducing scale, corrosion and mineral buildup on the element, achieving better performance and low maintenance.
Reliable&Durble: The 3.5kW tankless water heater comes with 5 protections. NFS approved, offer lead-free water. ETL safety certified, leakage and overheat protection device to ensure your safety. Stainless steel and copper component for high efficiency and durability
Smart&Considered Design: Small water heater designed with smart touch control & LED display, mini size, perfect for under sink installation. The minimum water flow for activation just need 0.4 GPM (Only for one sink)
Consistent Hot Water -On demand water heater only heats the water when you need it and no waiting for preheat.The temperature rise of 1.0 GPM is 22°F. Easy to get hot water between 85°F - 194°F in seconds. Enjoy instant and endless hot water
Rotatable LED Display: 120V tankless water heater features an upgrade rotatable digital temperature display and touch control panel, show you the easy reading output water temperature at real-time and setting ideal temperature just by finger. Note: This mini water heater is only suitable for sink use, not for bathing
Multi-angled Mounting: The compact size instant electric water heater requires a connection of 1* 40A circuit breaker & 8 AWG wire. Install close to outlet for energy saving. Can be mounted Multi-angled, ideal for kitchen, wet bars, school, hospital, hair salon and boats. Please make sure it is the right size for you: 3.5kW at 120V, product dimensions 7.8" x 6.3" x 3.9", water pipes fitting: 1/2" NPT male
Self Modulating - On demand water heater automatically adjust the power based on the change of inlet water flow and temperature, saving up to 50% energy consumption and preventing over-heating.
Instant Heating - 24 hours ready to continuously supply instantaneous hot/warm water at preset temperature throughout your home only when needed. NO standby energy consumption. NO wait for tank to fill up. MUTS HARD WIRED. Drawing only 110-120 Volts
Space Savings - 7.8W×6.3H×3.9D inch, compact small Point of Use water heater designed for Single Sink use, wall mounted fitting in small spaces throughout kitchen closet, bathroom sink, hair salons, bar counters and hotel receptions. Temperature ranges from 85°F- 131°F
Important Note - Please verify this unit is the right size for you: 3.5kW@120V, requiring 40A Circuit Breaker, 9AWG wire size and 1/2"NPT water connections
User Friendly - Touch control panel and digital temperature display, easy to set your desired temp. Lightweight and easy to install vertically facing up or down. Open tap to start the unit heating with activation flow rate of 0.4GPM.
Safe & Healthy - ETL certified and equipped with Multiple Protection from leakage, dry fire, over-heating and over pressure. IP25 waterproof. Stainless steel heating element and no storage water, preventing sediment / scale build-up.

Requires 1 x 30 amp breaker and 10 AWG wire
Can provide hot water for one sink at 0.5 GPM in warmer climates
Connection Fittings 1/2" NPT
Amperage Draw 29 amp. kW - 3.5 kW
For one sink at 0.5 GPM in colder climates the POU 6 is recommended
Max temperature rise @ .5 GMP is 47.8°F Max temperature rise @ 1GPM is 23.9°F Max temperature rise @ 1.5 GPM is 15.9°F
What to Look For in a best tankless water heater for hard water?
There are several factors to consider when you spend that money in best tankless water heater for hard water. It's more difficult to pick because the product is available in different sellers' wide assortment, functionalities, and characteristics. As a result, you should go through a reputable source of information on the item.
You're meant to relax since we're here to help you with that. The research is aided by more excellent technologies such as Artificial intelligence and Big Data. Thus, the information has a tremendous amount of influence and reliability.
Following, we've pointed out various characteristics of the best tankless water heater for hard water. You are projected to read the shopping guide here as well as the list of top models in the list:
Brass Vs. Plastic Drain Valves
Efficiency Rating
The difference between electricity and gas rates means that this rating doesn't give a good indication of the cost you could expect to pay for the unit. A gas heater with a lower efficiency rating will be more efficient than one that uses electricity. However, gas heaters are mucher than electric ones.
Because they don't have to run constantly to heat water, tankless heaters are significantlyer than storage tanks heaters. A tankless water heater can cut down on your energy bills by up to 40% depending on how much hot water you use. To determine the impact on your budget, it is better to calculate the annual operating cost for the hot water heater.
Space
Tankless Or Tank
Venting Needs
Digital Displays
Anti-Scale Devices
Tank Capacity
Gas Or Electric
FAQs
How Do Water Heaters Work?
A tank-style water heater uses a dip tube that has an outlet in the bottom to heat the cold water. The tank's temperature is monitored by an internal thermostat which activates either a heating element, or a burner that warms water to the desired temperature.
Dual heating elements are used in electric water heaters to heat the water. The bottom heating element heats the coldest water faster, while the top one warms the water if it becomes too hot.
A pilot light, or electronic ignition system for gas water heaters ignites the gas that is flowing to a burner. Before shutting off, the burner heats water in the tank until it reaches a desired temperature. The exhaust is then vented outside.
Water heaters that are tankless don't keep water. They heat the water by using either electric or gas heating elements. The temperature of the hot water is a factor in how fast it flows, however most units are capable of providing hot water at a flow rate between 2 and 7 GPM.
Can You Still Shower If Your Water Heater Is Leaking?
You can still take a hot shower even if your water heater is leaking. You can shower even if the leak becomes severe. It will just mean that you won't get hot water.
How Long Does A Water Heater Last?
Although water heaters come with varying lifespan expectations, many can last for between 8-12 years. Some water heaters can last up to 20 years. Your water quality can make a difference in how long your heater will last. Over time, corrosion can occur from heavy minerals or sediment.
Depending on which model you select, the manufacturer may offer different warranty terms. The most common warranty period is usually between 6 and 9 years.
How Often Should I Replace My Water Heater?
According to professionals, your water heater should be replaced every 10 years. A water heater cannot be guaranteed for this long. It is possible that your water heater will need to be replaced sooner than expected.
What Is The Best Compact Water Heater For Saving Space?
Mini-tank or tankless water heaters are compact and light, which makes them great for small homes that have less space.
What Are The Signs Your Hot Water Heater Is Going Out?
A failing water heater can be identified by a series of telltale symptoms, such as banging sounds inside the tank and a decrease in temperature.
Can Water Heaters Explode?
Electric and gas hot water heaters are susceptible to explosions. Explosions are rare, but can be caused by increased pressure in the heater, poor installation or maintenance, failure to set the temperature and relief valve (T & P), gas heaters, flammable liquids, or gas leaks.
How Do You Drain A Water Heater?
First, drain the hot water heater by flushing it with water at full pressure. After connecting the drain line, open the drain valve and close it again. The valve will dislodge any sediment, allowing the system to drain faster.
Then, disconnect your water heater from either the electric or gas power supply and shut down the main water supply. Next, disconnect the drain hose from the quick flush and open the drain valve. Once you let air in the tank, water will not flow out. You will need to remove the hot water pipe from the top of the water heater, and then move the pipe to the side. You will see the tank begin to drain.
What Is A Water Heater?
A boiler is often confused with a water heater. What is the difference between a boiler and a water heater? A water heater heats water to be used for showering, cooking, cleaning, or other purposes. The water heater heats cold water coming from the water supply pipe. It then gives you hot water ready to use for washing your clothes or running a faucet. Water heaters use water that's suitable for cleaning and cooking (potable). A boiler, on the other hand is designed to heat your home and heat water from the taps.
Gas Vs Electric Water Heaters: Which Is Right For You?
It's not cheap to install a water heater in your house. This is why it's important that you take some time thinking about how to charge your appliances. First, electric heaters offer the most sustainable option for the environment. If you choose one, it will be a better choice for your planet. Although electric water heaters work better, the price of electricity is higher than that of traditional gas options. You can still use your gas heater even if there is no power, so you have less to worry about during a crisis.
It's time to start buying when you've determined the best types of best tankless water heater for hard water and the characteristics you want. It's important to remember that you needn't rush out to a certain store or browse internet discounts just soon. You may quickly discover your pal thanks technological advancements, particularly the proliferation of selling sites.
Try to keep an eye on our site's regular to guarantee the latest deals best tankless water heater for hard water passes our standards. As a result, you'll be able to close the gap with them. Could you kindly provide us with feedback so that we can satisfy you guys, our customers? Wish you a great shopping experience!