Best Tankless Water Heaters 2018 – Gas, Propane, Electric (Reviews & Buying Guide)

Are you looking for a new water heater? If so, you’ve come to the right place. Perhaps your tank water heater has gone out, and you’re in need of a replacement, or you’re looking to upgrade your current water heater to something more efficient. Whatever the reason is, we’re here to help you pick the best tankless water heater for your home.


Top 10 Best Tankless Water Heater Reviews

BrandsTypesFlow RatesVoltsPrices
Rinnai RUC98iN Natural Gas10 GPM120V
Rheem RTGH-95DVLNNatural Gas9.5 GPM120V
Takagi T-KJr2-IN-NGNatural Gas6.6 GPM120V
Stiebel Eltron TempraElectric4.5 GPM240V
Eccotemp FVI-12-LPPropane3.6 GPM110V
SioGreen IR6000Electric 3.6 GPM240V
EcoSmart ECO 27Electric3 GPM240V
Marey Gas 10LPropane3 GPM2 D Cell battery
Camplux 10LPropane2.6 GPM3V
BOSCH TronicElectric 1.8 GPM240V

Here is a comprehensive review of the ten best tankless water heaters on the market today.

Rheem RTGH-95DVLN – Great Deal of Power Savings

This tankless water heater from Rheem offers a 94 percent energy efficiency rating. It offers a stainless steel condensing heat exchanger that offers electronic controls which help you control the flow of hot water on demand.

The unit is intelligently designed and compact enough to fit in even the smallest bathrooms at home or in the cottage. It can be housed up to 38 feet away from the area that it is servicing via PVP pipe like traditional water heaters.

The tankless designs allow for less water usage over time, and it provides a great deal of power savings because the water heater doesn’t draw on valuable energy to maintain the heat of the water 24 hours a day.

The Rheem RTGH-95DVLN meets rigorous industry standards for quality and reliability, and it is backed by a ten-year limited warranty on the heat exchanger, plus a one-year limited warranty on parts.

This tankless heater is run by natural gas and uses approximately 199,000 BTU to make the water heat up on demand. Installation of natural gas lines into your home may be required to have this tankless water heater installed, but once ready for installation; the tank takes no time at all to install.

It comes with a digital remote control so you can control the input and output of the water heater. And it has a 10-foot thermostat wired included for close proximity changes to the heating elements. What’s more, the unit is powered by a 120V power cord that comes with the package.

Pros and Cons

  • Uses less energy to produce hot water on demand.
  • Comes with everything you need to install it right away.
  • Remote, thermostat wires and power cord.
  • Great for a variety of locations in your home or cottage.
  • Can take a little longer for the water to heat up because there isn’t a constant supply of hot water sitting in a tank.
  • Can take some time to determine the best temperature for use for each person.


EcoSmart ECO 27 – Best for Multiple Bathrooms

The Ecosmart ECO 27 is but one of the many tankless water heaters offered by EcoSmart Smart Technologies. The ECO 27 offers savings of up to 50% off the cost of heating water in a more traditional hot water tank.

The unit features a digital temperature control that has a detailed degree control system, so users have more control over the hot water. Temperature ranges from 80 degrees Fahrenheit to 140 degrees Fahrenheit.

The unit features copper and stainless steel components that provide efficiency, durability and offers easy replacement of parts under if necessary.

It has a compact size that fits in any space, and its modern design means that even if you have to place it on a wall or a shelf in your home, it is not an eyesore. It also offers the patented self-modulating technology that Ecosmart owns that provides even more energy conservation.

When installing any new electrical component to your home, check to make sure that your electrical system can support the needs of a tankless water system. This unit requires 27kW, 240 volts.

As for the heating capacity, the ECO 27 can produce 3 gallons of hot water per minute at even the lowest temperatures. What’s more, it can support multiple bathrooms where more than one shower is being used at a time.

Pros and Cons

  • Patented technology heats water fast and consistently.
  • Can heat multiple showers and sinks without losing pressure and heat overall.
  • Company offers a multiple line up of models to fit your water heating needs.
  • Low power consumption and high water heating rates.
  • Lightweight and easy to handle during installation.
  • Measures only 17” x 17” x 3.5” in size.
  • The unit offers a remote control, but it is sold separately, which is not a deal breaker but is very inconvenient.
  • The limited warranty only covers electronics and the element of the heater; a more comprehensive warranty would be nice.


Takagi T-KJr2 – Best for Small Homes

This natural gas tankless water heater by Takagi offers a maximum water flow rate of 6.6 gallons per minute and uses only 140,000 BTU to heat the water being used. This model is one of the smaller units of indoor water heaters offered by this manufacturer, and it is a good size for smaller homes and cottages that house 1-2 people.

Despite its small size, it weighs a lot more than some of the other models in this water heater roundup. It comes in at a whopping 38 pounds, which might require two people for installation purposes.

The warranty on this model offers a ten-year limited warranty on the heat exchanger, a five year limited warranty on parts, and the manufacturer also offers a one-year limited warranty on labor. Despite it being only a year, a labor warranty is not common in the industry, so it is a nice feature in case something happens to your natural gas water heater.

The Takagi T-KJr2-IN-NG features an energy star rating and is available in some sizes for various uses, including an outdoor version of the tankless heater.

Pros and Cons

  • The manufacturer offers a better warranty than most water heaters which includes a one-year limited warranty on labor.
  • The tank is small, so it takes up less space.
  • Good for a small home, summer home or cottage.
  • The T-KJr2 is heavy despite its small size.
  • It offers a lower flow of water than other models on the market.
  • Might take a while for the water to heat up because of its small size.


Rinnai RUC98iN – Best Space Saving Design

The natural gas tankless water heater by Rinnai offers a space-saving design that means it can be installed almost anywhere you would need to get access to hot water on demand.

Think the cottage, the summer home, or your small apartment. Don’t let the small size of this tankless heater fool you though; it offers a great deal of heating power with a small footprint.

Using 199,000 max BTU, this model offers ultra-low emissions and uses a condensing technology to produce efficient water heating capabilities. With temperatures ranging from 98 degrees Fahrenheit to 140 degrees Fahrenheit, the water heats up fast and consistently.

The warranty offered by Rinnai features a 12-year limited warranty on the heat exchanged housed inside of the water heater. 5-year warranty on parts and a one year warranty on labor for residential applications. Similar to the Takagi T-KJr2, the bonus of a one year warranty on labor is a nice touch from the manufacturer.

This water heater is a little on the large side of some of the tankless heaters reviewed so far: it measures almosts 19” in width and 26” in height. But it is still very small for what it offers in on-demand water heating options.

It is a little heavier than the other models as well, coming in at over 60 pounds total. Despite this, the flow rate of almost 10 gallons per minute makes it super fast and provides a great water flow overall for homeowners or apartment dwellers.

Pros and Cons

  • Great water flow of almost 10 gallons per minute.
  • Energy Star rating.
  • Small footprint.
  • Low voltage.
  • Comprehensive warranty including one year on labor for residential applications. And an option to buy an additional 2-year warranty for commercial applications and installations.
  • Despite its small size, the Rinnai RUC98iN is one of the heavier ones in the lineup.
  • Offering 10 gallons of water per minute could add up fast if you take long showers or let the water run while you are doing dishes.
  • For commercial use, the tank has to be set for up to 185 degrees Fahrenheit, which could be dangerous if exposed to skin.


Stiebel Eltron TempraTop Rated Electric Heater 

The Eltron Tempra Plus tankless water heater by Stiebel offers digital temperature control. This unit does not require venting, which means it requires less effort to set it up and maintain it over time. It offers a sleek design that measures 15” in width, almost 17” in height, and nearly 5” in depth.

Homeowners and apartment dwellers can expect to save up to 20% of their home electric bill based on their previous bills using a traditional hot water tank.

This unit is electric, and not powered by natural gas like some of the other water heaters in this review. Which means that the installation is minimal and it can be installed in a number of locations that don’t have access to natural gas.

The unit requires 208/240 volts of power to run, and it is backed by the proven reliability of German design and functionality in the industry. This tank is often priced at a more reasonable rate than other tanks. And that makes it popular amongst first time tankless buyers because they aren’t sure if they will like the model and water flow.

This model of tankless water heater is just one of the many models offered by Stiebel, and the range is staggering. It just goes to show that the company knows a thing or two about the various needs of homeowners in different areas and of different sizes.

The unit is very light: less than 16 pounds overall and coupled with its small footprint makes it easy to install, easy to move if necessary, and easy to maintain.

The Stiebel Eltron Tempra Plus offers a limited three-year warranty, but the product must be installed by a licensed professional in order to activate the warranty.

That’s an important distinction from the other models in this review because although it is light and easy to install if you want the warranty. You’ll need to pay for the installation fees which can range up to $1000USD depending on your location.

Pros and Cons

  • Small and compact design makes it ideal for home, cottage or other small dwellings.
  • No need to ventilation this unit.
  • Requires little voltage to run.
  • Electric, so no need for natural gas installation and maintenance.
  • Offers warranty but with stipulations to activate the warranty.
  • The stipulation to activate the warranty only after it has been installed by a professional makes this a hard sell. The manufacturer boasts about how easy the unit is to install but then sets limitations on the warranty.
  • Complaints of issues with water chemical composition rotting the units from the inside out – if you have hard water, you might need to get a water softener to accompany this unit depending on where you live.


Eccotemp FVI-12 – High Capacity Propane Heater

This high capacity, low energy propane tankless water heater by Eccotemp offers a digital temperature display with independent gas and water controls to get the temperature just right for your needs. This unit promises no more cold showers and promises to run hot the first time, every time.

Powered by an intense propane flame inside the unit, the water becomes instantly hot, and the unit comes ready to install immediately. It is for indoor use for homes, small houses, apartments and you can even use it at the cabin.

Economical, using only 2 watts and 1.07 amps of power during operation, you can expect to save money over the long run with this efficiency water heater. It offers a maximum water flow rate of 3.6 gallons per minute which means that you won’t waste a lot of water trying to take a shower or do the dishes.

However, this unit is not recommended for multiple users at a time, following the directions will make your water heater last that much longer.

What’s more, this sleek unit simply plugs into your standard electrical system at home so you can install it quickly and easily yourself. You will need a separate propane tank ranging from 20 lbs to 100 lbs, but they are easy to obtain in all areas.

The unit weighs about 33 pounds and measures 15” in length, 4” in depth, and 24 inches in height. It’s tall and can be tucked away behind a door or other storage area for easy hiding and easy access in a number of locations including behind a door, in a closet, or in a cabinet away from view.

The company offers 24 hours, seven day-a-week customer support so even if your electrician or plumber can’t come in the event of an emergency, you can contact the company for advice and support. The unit also offers a limited 2-year warranty on the heating element.

Pros and Cons

  • Instantly hot water provided from the propane source of heat.
  • Low flow rate of 3.6 gallons per minute cuts down on over usage of water and waste.
  • This unit offers low power usage which can result in more savings overall.
  • Moderately heavy but small footprint for the overall size of the unit.
  • Ideal for small homes with only 1 or 2 people in the residence.
  • Short warranty that only covers the heating element.
  • Needs a separate propane tank which can add up over time to the cost savings you might have seen on your water or electrical billing statement.

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Marey Gas 10L – Best for DIYer

Promising to save consumers up to 60% on electricity bills for the water heating portion of your bill, the Marey Gas 10L offers water flow rates of up to 3 gallons per minute. Despite its small size and ability to save you a lot of money, the tankless heater can support multiple points of use including showers, dish washing, and laundry.

What’s great about this water heater is that it does not require electricity. This is a life saver for homes that experience frequent power outages, especially if you have small children at home. The unit offers adjustable gas and water controls and uses natural gas to power the unit easily and quickly.

The Marey Gas 10L measures 24 inches high, 14 inches wide and 7 inches deep. It is a little thicker than other models in this review, but because it doesn’t require electricity, it’s a great little number to install in your home or even cottage. What’s more, the unit only weighs about 21 pounds making it easy to move around during installation and easy to move if required.

Like some of the other models of tankless water heaters listed here, the Marey Power Gas 10L can be easily installed by the homeowner in just a matter of hours, depending on how much preparation of the installation site has to be done. The unit does require 2 D-cell batteries to keep the ignitor flame ready for heating on demand.

This manufacturing company offers good customer service support to its customers, but not on a 24-hour basis. It is available Monday through Friday during regular business hours CST. The manufacturer also offers a five year limited warranty on all parts.

Pros and Cons

  • A true do-it-yourself unit.
  • Can support multiple points of drawing water.
  • Lightweight and compact for easy installation.
  • Great money saving option for homes.
  • Offers 50 feet of support from the point of installation to the source of the water.
  • Doesn’t have digital controls, which is disappointing because it is expected in units like this.

Camplux 10L – Best for Outdoor 

The only outdoor tankless water heater in this roundup, the Camplux 10L Outdoor portable water heater is powered by propane and great for the campsite, cottage, hunting cabin and more. It offers anti-freeze protection, flame failure device, and an automatic shut off for power consumption and safety when not in use.

The unit offers a compact and lightweight design measuring 21” high, almost 13” wide, and 8 inches deep. It comes with a number of accessories to help you get the most out of your camping or cabin experience including the complete Camplux tankless water heater system.

This system includes a shower head with a pedestal for storage, premium construction shower hose that measures 5 feet long; a CSA approved gas hose and regulator, a garden hose, a gas inlet connector to attach to your propane tank, and an accessories package that allows you to hang the unit and repair it.

The Camplux 10L provides instant hot water thanks to the propane system so you can wash your car, boat, animals, or even use it as an outdoor shower at the camp or in your pool house.

It provides 2.6 gallons of water per minute and offers a unique combustion technology that provides steady heat and reliability anywhere you hook it up. What’s more, you can work the system on a modified 12V amp system for even more options for hot water on the go.

Unfortunately, while this water heater has many benefits and features, the water that comes through the tank should not be used for drinking water, nor is this unit approved for indoor use in a residential home.

Hooking up the Camplux tankless outdoor water heater is as easy as hooking up a propane tank to a barbeque, and can provide hot water seconds after it is hooked up.

Pros and Cons

  • CSA approved for outdoor use.
  • Can be used on a 12V system.
  • Small and lightweight, weighing only 18 pounds.
  • Portable and easy to move around for travel and more.
  • Hooks up to a propane tank in seconds and hot water is instantly accessible for cleaning cars, boats, and more.
  • Good water pressure and flow for easy cleaning of a number of items, including yourself at the cottage or cabin in the woods.
  • Rated for outdoor use only.
  • The hot water is not intended for potable usage.
  • Can be used in colder weather but must be stored indoors for longer periods of cold.

BOSCH Tronic 3000 – Best for Under-Sink 

Backed by one of the best electronic and appliance brands in the world, the BOSCH Tronic 3000 offers electric power and provides hot water on demand in seconds. It offers easy installation and is small enough to fit under a kitchen or bathroom sink.

The unit provides a 98% efficiency rating and doesn’t waste power when not in use. It can only be operated on a 240V power source, however. The unit is available in several sizes, but they can all be mounted on the wall or under your sinks, depending on the size.

However, despite the size of water heater you choose, all of the units are incredibly lightweight, weighing only 5 pounds and they are all the same size: 6.5″ x 12.25″ x 3″ overall.

Typical usage does not require an additional pressure relief valve, and for many years of enjoyment, the unit should be installed by a professional.

The BOSCH Tronic 3000 boasts an energy star rating. And the company does offer a limited warranty and customer service to help with issues or concerns. Before attempting to install the unit yourself, check with the manufacturer to ensure that doesn’t void the warranty, like some other models in this review.

Pros and Cons

  • The unit offers great efficiency ratings.
  • Small and lightweight across all models.
  • Modern design and easily blends in with surroundings.
  • Backed by one of the best brands in the business.
  • Can be installed anywhere from under the cabinets to on the wall.
  • Limited warranty from such a great brand name.
  • Some customers have complained of the hi-temp setting being switched on without warning causing issues with the temperature of the water coming out of the unit.


SioGreen IR6000 – Best for Hard Water

The SioGreen IR6000 tankless electric water heater offers 3.6 gallons per minute of water pressure and uses a unique coilless technology and infrared technology to heat the water quickly. The unit offers a corrosion free build and uses less power because only the water you use is heated, rather than having hot water sitting in a traditional tank waiting to be used but needing to be kept hot for days sometimes.

This unit is good for areas that have hard water because it doesn’t produce calcium and limescale deposits the way some other tankless heaters might. The water heats in seconds using a patented quartz heating element, so the water doesn’t come into contact with metal.

There are a number of models available for residential and commercial use under this brand, but this model is ideal for family homes of 4-5 people. It is also ideal for multiple draws on the system at the same time so more than one shower can be running at a time.

The unit can be installed easily without a lot of interruption to the flow of water. It offers adjustable temperature settings, and it doesn’t require ventilation.

Small and compact measuring 20” x 14” x 6” and weighs about 27 pounds in total. It doesn’t require any batteries, and there is a limited manufacturer’s warranty available for purchase as well.

Pros and Cons

  • Lightweight and small in size.
  • Patented design heats water fast.
  • Offers 3.6 gallons per minute of water pressure.
  • Unique infrared technology for heating water on demand.
  • Offers both commercial and residential applications.
  • Good for moderate sized families.
  • The water can take a few seconds to heat up so it’s not “instantly” hot as promised.
  • The unique design and element use might make it hard for professionals to fix.

Buying Guide

When it comes to buying a tankless water heater for your home, apartment, cottage, or anywhere else you need a source of hot water; there are a number of things to consider.

The first thing to consider is whether or not you are going to be installing the water heater yourself. Some models won’t honor a manufacturer’s warranty if the homeowner installs the unit themselves. This is an important thing to note because if you have troubles later on, it can be difficult to get the help you need to fix your water heater.

The next thing you need to consider is how many sources of water do you need to support. For example, if you have 2 or 3 bathrooms in your home and multiple people will be using the showers or sinks at a time. You will need a robust and higher gallon flow water heater to support that kind of use.

This typically means the water heater you choose will be bigger and potentially heavier than lesser flow models, but it’s an important distinction to make.

If you live alone or have a smaller home, you can probably get away with getting a smaller unit. Which will cost you less money up front and potentially overall as you won’t be using as much water as someone who lives with multiple people or has more than one bathroom or shower source.

The third thing you want to think about is whether or not you want a tankless water heater that is electric, runs on propane or runs on natural gas.

If you don’t have access to natural gas in your area, then a number of models in this review will be irrelevant for you. However, most areas these days do have it so you should be fine. Be sure to check your local area to be sure before you buy.

Electric water heaters can save you money overall, and so can propane heaters. But the propane water heaters still require you to purchase propane and make sure you don’t run out. This can mean cold showers in the morning if you forget to get a new supply of propane.

Finally, before you buy a tankless water heater, be sure to see how much voltage you need to run the heater itself. Some models don’t require electricity at all, and this won’t be an issue if you buy those. But if your water heater needs a power source, you will need to ensure that your home is properly wired to support the installation of such a device.

One last thing, if you need a water heater for outdoor use, be sure to purchase a CSA approved water heater for the outdoors. Nine out of the ten models in this reviews are not meant for outdoor use.

Not only can this void your warranty, but it can create a dangerous situation for you or anyone else using the water heater in a way that was not intended for it to be used. If you are not sure if the water heater you are going to buy is indoor or outdoor, ask for assistance at the location before you buy it.


How Tankless Water Heaters Work?

A tankless water heater does not need a centralized water tank. It is connected to the supply system. When you turn on a water tap, the cold water passes through the unit where an electric element or gas burner heats the water instantly. The system delivers a constant supply of heated water. You won’t have to wait for a storage tank to fill up with hot water before you can use it.

The system typically provides hot water at a reliable rate of around 2 to 5 gallons per minute. Tankless hot water systems powered by gas have higher outflows than electric systems. However, gas-fired models are limited in the amount of hot water they can provide in large households.

It may be difficult to have hot water running in your bathtub and dishwasher simultaneously with a gas-powered system. The solution to this problem is to install multiple tankless water heaters for different appliances separately.


Types of Tankless Water Heating Systems

There are several types of tankless water heating systems. It is therefore imperative to understand the differences so you can tell which water heater best suits your needs. Let’s take a quick look at some of the major types of tankless water heaters.

  • Non-condensing

The non-condensing unit is the first generation of tankless water heaters. The unit has a heat exchanger that provides you with hot water whenever you need, with an efficiency factor or EF of between .82 and .85. The EF generally translates to around $75 to $80 annual savings in your power bills compared to the traditional water heater that uses a tank.

A non-condensing unit, however, has the disadvantage of delivering hot exhaust, which makes it imperative to install expensive stainless steel venting. It also has lower efficiency especially when you use hot water in frequent short draws, such as washing your hands.

The main advantage of non-condensing tankless water heaters is that they are less bulky and cheaper than condensing units.

  •  Condensing

This is the second generation of tankless water heaters that feature a second heat exchanger to eliminate heat from the exhaust and heat the water further giving you a higher energy efficiency of between .92 and .94. The higher EF translates to annual savings of around $90 to $100 in energy expenses.

The other advantage of these units, besides higher EF, is the fact that they can be vented using less expensive PVC materials. The major downside of condensation units is that they come with a higher price tag than non-condensation units.

  • Condensing hybrid

A condensing hybrid unit can be considered as the third generation of water heaters. It is not entirely tankless but a more advanced system that comes with a small 1 or 2-liter holding tank, hence the name hybrid.

The small tank works as a reservoir of already heated water and eliminates the disadvantage of lower efficiency of short regular draws found in both non-condensing and condensing units.

Hybrid units have an EF of .92 to .96, which translates to annual savings in the gas of around $120. They are more efficient but come at a higher price.

  • Point of Use (POU)

A Point of Use (POU) water heating unit eliminates heat loss in the hot water distribution system. As the name “Point of Use” implies, the water in this system is heated as close as possible to the outlet, such as the sink, bath, or shower, rather than from a central heater.

Point of Use water heaters helps to boost water temperature at a fixture located away from the central heater. The system provides better energy efficiency, especially in large premises or homes.

However, installing multiple POU heaters separately for your kitchen sink, bathroom, and laundry comes at a higher cost.


Fuel Supply

Selecting the right type of fuel for your tankless heater is an important consideration. The fuel type you choose will have an impact on the size, usage, and energy efficiency of the unit.

Ultimately, it will determine how much you spend annually on your hot water needs. It is also essential to choose the right fuel type when building a new home as changing fuel sources once the unit has been installed can be quite expensive.

There are basically three types of fuel choices for tankless water heating systems, namely gas, propane, and electricity.

Your choice will depend on the type of fuel readily available in your area but if you are lucky to have all options close at hand, then compare costs and energy efficiency of each option before making your decision.

To help you make an informed decision, let’s look at each of the available fuel options.

Tankless water heaters powered by gas are normally less expensive than electric or propane powered units. They have a better performance than electric units and have better energy savings from an operating costs perspective.

A gas unit heats water fast giving you quick response time and a consistent high heat output. However, they require professional servicing regularly, which may add up maintenance costs over time.

Propane tankless water heaters can significantly reduce your energy costs. With the rising costs of utility, heating water using propane provides a more cost-effective and energy efficient option than electricity.

Another major advantage of propane tankless water heaters is the fact that they are eligible for federal tax rebates of around $300 and other state incentives. The propane unit saves you money in the long term while providing your home with a constant supply of hot water on demand.

One of the major advantages of tankless water heaters powered by electricity is that they are comparatively cheaper to buy and install than gas and propane units.

The drawback is that they have a higher energy demand to operate. Additionally, if you plan to upgrade your home’s electrical system, the tankless water heating unit will significantly increase the cost of the project.

Electric systems have a more straightforward design than tankless gas systems. They are simple to repair and require minimal maintenance thanks to their simplistic design.

Compared to gas units, electric tankless water heaters are much cheaper, with price tags of $500 to $700 while a gas unit costs $1,000 or more. They are easier and less expensive to install too. They don’t produce exhaust gases, which eliminates the need for venting. Electricity doesn’t produce greenhouse gases which makes these units more environmentally friendly than their gas or propane counterparts.

The price of electricity is more stable than gas. It rises at a much slower rate, which makes this type of demand water heaters one of the most preferred choices for most homeowners.



Tankless water heating systems are more energy-efficient than traditional storage tank water heaters. For instance, a home with a daily usage of about 41 gallons of hot water or less has an energy efficiency of between 24 and 34 percent when it has a tankless water system installed.

A home with a higher hot water demand of up to 86 gallons per day has 8 to 14 percent more energy efficiency with a tankless system compared to one with a hot water storage tank unit.

The energy-efficiency provided by tankless units is because they prevent standby heat loss characteristic of storage water heaters. With a demand water heater installed at each hot water outlet, you stand to achieve higher energy savings of 27% to 50%.

According to estimates by ENERGY STAR, a family with an ENERGY STAR qualified demand hot water unit saves around $100 or more every year in utility expenses.

Despite the higher cost of installing this type of water heater, compared to a traditional storage water heater system, the unit lasts longer and has lower energy and operating costs. The savings it gives you on utility costs will offset the purchase and installation costs in due time.


Cost of Installation

One of the major drawbacks of tankless water heaters is that they cost more to purchase and install than standard tank storage water heaters. The cost of buying and installing a tankless unit in a typical two bathroom home can be twice that of a standard water heater.

However, with a propane system, you are eligible for a $300 federal tax credit and other state and local rebates available in your area. The system has fewer maintenance costs than the water storage system and will only need to be replaced twice in its entire lifetime. It’s a better long-term investment despite the higher purchase and installation costs.

So what are the typical costs of installing a demand hot water system in your home? Installation costs range from $1,500 to $2,000 depending on factors such as type, size, and model.

Installation costs will also depend on other factors such as materials, labor, and permit costs in your region as well as the brand and capacity of the water heater you intend to install.



Tankless units have many advantages compared to standard stored-water heaters. Here are some of the key benefits you get when you install a tankless water heating system in your home.

  • Energy efficient

The unit only operates when a demand for hot water arises, which reduces energy costs for up to 35% or more per year. ENERGY STAR states that there are units with energy factors as high as 95 percent. They are more energy efficient than standard hot water tank units.

  • Efficient in water use

With a tankless system, you are assured of getting hot water every time you need it. Your family enjoys a constant stream of hot showers whenever they need it.

  • Unlimited hot water

The system allows you to have hot water in multiple outlets of fittings at the same time. You can be taking a hot shower while the dishwasher and laundry are running at the same time. It allows you to take full advantage of your Jacuzzi tub or Roman bath without fear of running out of hot water.

  • Durable

Tankless units are more durable than most standard hot water tanks. They come with warranties of 10 to 15 years and can last as 20 years before you consider getting a replacement. Standard tanks have a warranty of around 6 years and will only last between 8 and 10 years. You’ll typically go through two or three tank units before you can replace a single tankless unit.

  • Saves money

A demand water heater saves you money. It only heats water when you need hot water while the tank system wastes energy by heating water when it is not required. The energy saved by a tankless unit reduces your utility costs by up to 30 percent every year.

  • Can be installed anywhere

Hot water on demand units don’t take up much space of your home. They can be installed just about anywhere in the house. In most cases, they are hung on the wall either inside or outside the house depending on your local climate. It helps you save valuable closet or floor space.

  • Provides cleaner water

A tankless unit provides cleaner water too. Standard water heaters can potentially build upscale and rust inside the tank over time, but a tankless unit gives you cleaner and fresh hot water all the time.

  • Reliability

Reliability is another advantage you get from a hot water on demand unit. With a properly sized unit, you’ll always have a continuous supply of hot water at a preset temperature. The units provide as much as 7 gallons of hot water per minute and will never run out of hot water.

  • Safety

The units also score high in terms of safety. They only operate when needed to unlike standard tank units that are always turned on and susceptible to wear and tear. The latest hot water on demand models come with innovative safety-enhancing features such as water pressure and flow monitors. They automatically turn off in case of system failure.



There are a few drawbacks to tankless water heaters including the following:

  • Higher upfront costs

They have higher upfront costs than standard tank units. The unit costs almost twice as much as the conventional storage tank but is more energy efficient and saves you more money from a long-term perspective.

  • Higher installation cost

They have a higher installation cost bearing in mind that you’ll need pricey venting for some models.

You may need to install a water softener in places with hard water. This is necessary as hard water could potentially damage the unit.


Sizing a Tankless Water Heater

Tankless water heaters are rated according to the maximum temperature they can provide at a specific flow rate. To determine the size of a tankless water heater, you’ll need to know its flow rate and the rise in temperature needed in the house.

When considering the right size of unit for your home, avoid making the mistake of undersizing the unit just to save money. Here are a few steps to follow when selecting the right size of a demand water heater.

1.Number of devices

Find out the maximum number of fittings or outlet devices you need and determine their total flow rate in gallons per minute. Get the total flow rate which is actually the rate you’ll want from the heater.

For example, if you expect to run a faucet with 0.75 gallons per minute flow rate simultaneously with a shower head that has 0.26 gallons per minute flow rate, you would need a heater capable of providing at least 3.26 gallons per minute. You can reduce flow rate by installing water fixtures with low flow.

2. Temperature rise

Find out the required temperature rise by subtracting the temperature of incoming water from the output temperature you need. You can assume incoming water has a temperature of 50 degrees F if you don’t live in warm climates and, as most people do, expect to heat your water to 105 or 115 degrees. In this case, the expected temperature rise should ideally be 55 degrees F.

3. Sizing

From the example provided above, the right size of tankless water heater should be able to give you a temperature rise of 55 degrees F with a flow rate of 3.26 gallons per minute. You’ll also need to consider other important factors such as how much hot water you need at a time and if you intend to run two hot showers at the same time together with your sinks.

Your expected hot water usage, budget, and type of tankless water heater system you intend to install will help to determine which size best suits your home.


Top Brands Tankless Water Heater Reviews

Let’s look at some of the best brands worth looking at when shopping for the best tankless water heaters.


Rinnai is a well-known brand in the indoor gas tankless water heater industry. They manufacture high-quality propane and gas-powered instantaneous water heaters for both residential and commercial facilities.

Their products feature multiple venting options and come in sleek, compact designs. For example, the Rinnai RUC98iN Ultra Series is a small 10-inch thick unit that weighs 6.7 pounds. It has an elegant gunmetal gray exterior and control buttons complete with a digital display on the front panel.

If you are looking for a good gas or propane tankless water heater for residential or commercial applications, then the Rinnai series is a great option. However, their installation is a bit tricky and best left to a professional plumber.


Rheem is another leading brand of tankless water heaters specializing in electric powered units. One of their well-known products is the Rheem RTE 13 which is a compact unit weighing just 8.5 pounds. It has a width of 7.25 inches and is 10 inches tall.

The unit has a gray metal box and can easily be installed without getting it out of the box. Users can easily control temperature from a convenient front panel with green and red LED indicators. It has a thermostat dial with nine settings.

The RTE 13 can be used to provide hot water in both residential and commercial properties. It is, however, most suitable as a point-of-use tankless water heater. It is energy efficient but not designed for cold climates.


Homeowners seeking to invest on tankless water heaters should pay attention to the Takagi. One of the significant features of this brand is the comparatively more affordable price.

Despite its lower price, the unit comes with most of the key features found in other tankless water heating model on the market today.

Takagi T-KJr2 is a natural gas -powered water heater that’s perfect for all your residential home’s instant hot water needs. It is highly energy efficient which saves you from high power bills.

The unit consumes less energy but delivers a high output of hot water on demand. It comes with both inlet and outlet thermistors which help to monitor temperature at all times.

The unit has a maximum flow rate of 6.6 gallons per minute which is more than you need for domestic usage and runs on a 140,000 BTU. It has a portable size and is lightweight too.

Sio Green

Sio Green is a leading name in infrared tankless water heaters. For instance, the company’s Model IR8000 is designed for both residential and commercial applications. It is ideal for large homes as well as medium to large commercial facilities with a demand for up to 4.4 gallons per minute of hot water.

It is a powerful and highly efficient water heater that uses Quartz infrared heating elements to heat water. It is made for hybrid applications, which allows you to use the unit to upgrade an existing standard water heating unit that uses a tank.

By integrating the unit to a traditional gas or electric tank heater, you can enjoy the benefits of a tankless system such as a continuous supply of hot water whenever you need it and more energy savings.

Stiebel Eltron

The Stiebel Eltron brand has been in the water heating industry for more than 90 years. The company is known for manufacturing efficient products ever since they sold their first immersion water heater in 1924. Their line of digital tankless electric water heaters is a good testament to the company’s passion for innovation and technology.

A good example of their technologically advanced tankless water heating systems is the Tempra Plus model. It comes with heavy duty electronics, single flow sensor design, advanced flow control, and a convenient hinged cover that gives users easy access to the unit.

It is an energy efficient unit capable of saving you around 15 to 20 KWH of energy compared to the traditional tank heater. It allows you to adjust water temperature from accessible dials easily and does not take up much space in your home. It is one of the most advanced electric tankless water heaters on the market today.


The Marey ECO 270 Electric water heater is the bad boy of tankless water heaters. You can count on this unit to provide you with properly heated water on-demand given that it has 27Kw of power and 112.5 Amp.

Its Smart technology and digital panel automatically set your water output to your desired temperature. You only need to set it once, and it will continuously give you hot water in all seasons, winter or summer. It is sediment and limescale proof, thanks to its patented technology.

Compared to a traditional tank water heater this unit will save you up to 60 percent of your electric bill. It is ideal for homes with up to 4 bathrooms.

Other key features include durability and Nickel-Chromium heating elements. It is certified for use wherever you are in USA and Canada.


Ecosmart tankless water heaters feature cutting-edge technology in the on-demand water heating systems industry. They have a sleek design and can easily be mounted on a wall.

They come with Patented Self Modulating technology which gives you up to 50% savings on your energy bills compared to traditional tank water heating units. The brand is a leading name in green energy products and innovation. The units have a high energy efficiency rating of 99.8 percent.

Other key features include digital temperature settings that you only need to set once to get a constant supply of hot water at your preferred temperature every day. The brand provides excellent customer care and limited lifetime warranty for their tankless water heating products.


One of the best things about this brand is the fact that they provide customers with top-of-the-range tankless water heating units at an affordable price.

An excellent example is the Eccotemp L10 portable tankless water heater that can be used in a wide range of facilities including your summer cabin, RV, cottage, and home. You can easily install the unit anywhere you need to have a constant supply of hot water whenever you need it.

The unit gives you up to 2.5 gallons per minute of hot water, which you can run in multiple outlets at the same time. It delivers hot water with temperature ranging from 80 to 145 degrees F.

If you are looking for reasonably priced yet versatile tankless water heater that you can install just about anywhere, then the Eccotemp L10 Portable model is just perfect for you.


Noritz is another leading name in the tankless water heaters industry. They’ve been in the industry for more than 60 years. Noritz introduced the first electronically controlled tankless unit way back in 1981 and had continued to be a leader in development and manufacture of advanced tankless units that deliver superior hot water and energy savings.

Noritz tankless heaters provide numerous benefits to both residential and commercial users. They are convenient to use, eco-friendly, provide significant energy saving, are reliable and long-lasting, and ensure that you get fresh and clean water whenever you need it.

Good examples of Noritz tankless water heating products include the Noritz Eco-Tough Series and the NRC661 that uses natural gas and has an EF of 0.91. Noritz provides consumers with cost-effective and reliable tankless hot water solutions.


Bosch instantaneous water heaters deliver optimal performance, energy efficiency, and are environmentally friendly. For instance, the Bosch Greentherm Model C 1050 ES comes with an Energy factor (EF) of 0.95. It has an ENERGY STAR rating too.

The unit provides other benefits such as an automatic fully modulating bypass that ensures temperature stability, an inlet water filter, new venting options, and a water heater mobile app where you can easily download technical documents.

Another great Bosch tankless water heater model is the Therm 520 PN that comes with push-button ignition and a modulating gas valve that maintains constant water temperature in varying flow rates.

It is a perfect tankless water heating unit for smaller households that require a maximum of two hot water outlets running at the same time.


Navien tankless water heaters feature advanced condensing technology. They have a simple design and are easy to install. They can be incorporated into an existing gas line, which eliminates the need to install an additional gas supply line when installing the unit. They use 2-inch PVC venting which is more affordable and easier to install.

Key features and benefits include seamless installation using existing ½ inch gas line, premium condensing, help to eliminate cold water sandwich problems, have a built-in recirculation pump that saves you money, two stainless steel heat exchangers, and ultra-low emission of NOX among others. If you are looking for a less expensive to install tankless water heater, Navien is your best option.



If you are looking for the best tankless water heater on the market today, go for the Rheem RTGH-95DVLN. We like it because it offers the most robust options for natural gas water heating. Has an excellent warranty, offers a great water flow of 9.5 gallons per minute and is small enough to store anywhere in your home.