Best Tankless Water Heaters Buying Guide & Reviews


What Makes a Good Tankless Water Heater

The water heater market has essentially seen major developments over the past decade. What we have now are on-demand tankless water heaters that are operable through electricity. natural gas, and even batteries.

In that, there are different models that support indoor and outdoor use. So from the looks of it, you will realize that the market is flooded with these modern heaters, each of which has their own unique features that contribute to their selling points.

Though the water heater market is intensely diversified, we have created an outline of what constitutes a good water heater. To begin with, water heaters available today are geared towards energy efficiency in a compact and lightweight model.?Makers like Rheem, Eccotemp, EcoSmart, and Bosch have their own patented technology that helps users save money on water heating bills down the line.

The next thing to consider is how functional a water heater is in different climates. What many users don’t know before buying a water heater is whether it is suited for their climate. In harsh cold weather, the components of a water heater might not be able to provide similar energy efficiency as in moderate climates. For that, a water heater that is highly insulated will allow the user quick and consistent supply of hot water.

Last but certainly not the least is the flexibility of a water heater. Remember that this is an on-demand tankless water heater buying guide. In other words, the water heaters that we’ll discuss here are not made for standalone use in large homes, apartments, offices, and other areas. The tankless water heater market is dominated by some high end models that can work great as standalone units, complimentary units to the main water heating system, and of course, point of use applications.

Best Tankless?Water Heaters Comparison Table?2014

NameRatingPriceConfigurationGallons Per MinuteEnergy-Efficiency RatingsIdeal For
Rheem RTE 134$$Electric, Tankless4 GPM★★★Standalone, Complimentary System, Indoor
Eccotemp L54.5$$Battery Powered, Tankless1.4 GPM★★★★Standalone, Point of Use, Outdoor
EcoSmart ECO 274.5$$$$Electric, Tankless3 GPM★★★★★Standalone, Complimentary System, Indoor
Bosch Ariston GL2.53$$Electric, Mini-Tank2.5 GPM★★★Point of Use, Complimentary System, Indoor
EcoSmart ECO 184.5$$$Auto2.5 GPM★★★★★Standalone, Complimentary System, Indoor
Bosch Ariston GL4S4$$Electric, Mini-Tank4 GPM★★★Point of Use, Complimentary System, Indoor
EcoSmart ECO 114.5$$Electric, Tankless2 GPM★★★★Standalone, Point of Use, Indoor
Rheem RTE 94$$Electric, Tankless3 GPM★★★★Standalone, Complimentary System, Indoor
Takagi i-T-KJr2-IN-NG4.5$$$$Natural Gas, Tankless6.6 GPM★★★★★Standalone, Complimentary System, Indoor
Eccotemp L104$$Battery Powered, Tankless2.6 GPM★★★★Standalone, Point of Use, Outdoor

Different Types of Tankless Water Heaters

The tankless water heater market is dominated by high end models from renowned manufacturers like Rheem, EccoTemp, EccoSmart, and others. The increasing competition results in users getting cut price deals on water heaters. The water heaters that were once out of the budget are now considered as a viable investment in the long term. Tankless water heaters became popular for their flexibility in use and that is something that the industry has retained to this day.

Essentially, there are two main specifications in on-demand tankless water heaters; mini tank and tankless. As the name suggests, mini-tank water heaters feature a small tank that can store hot water for immediate use. On the other hand, tankless water heaters cannot store any hot water. They raise the incoming water temperature and then deliver hot water supply through shower heads, sinks, or wherever they are installed. Depending on what model you purchased, the water heater will be able to offer around 2 to 6 gallons of hot water per minute.

All types of tankless water heaters are available for indoor and outdoor uses, so that’s another factor that differentiates the class. Indoor water heaters are generally available in tankless configuration, and are ideal for homes, offices, or areas where hot water need is low. Outdoor water heaters are generally available in mini tank configuration, which means they are designed for outdoor water flow rates.

The tankless water heater market is still relatively new with room for growth. From the looks of it, the market is heading towards more energy efficient and functional models that will soon dominate the market.

Tankless water heaters are operable with electricity or natural gas. They commonly run on electricity and natural gas, but can be battery powered if they are equipped with mini-tanks. Hence, that is another thing to consider for potential users as some areas might not have regular electricity supply, while other areas may have the same with natural gas.

Components of a Tankless Water Heater

While the tankless water heater market is flooded with unique models that claim to offer exclusive features over their competitors, there are few components and features in them that are similar, including:

  • Heat Exchanger

    This is the most important component in any water heater as it is responsible for converting the incoming water into hot water.

  • Modulating Temperature Control

    Depending on what model you buy, the water heater can be self modulating or manual. This ensures that there is consistency in the outgoing water temperature.

  • Temperature Control Knob

    The temperature control knob allows the user to set varying degree of temperatures of hot water that the water heater will provide. Again, depending on the model, the temperature knob can increase or decrease water temperatures by increments of 1 to 5 degrees with a single turn. In some high end models, the temperature can be controlled via a remote control.

  • Water Inlet Lines

    Since most tankless water heaters are designed for cost effectiveness, they tend to have just one water inlet line. That being said, there are models that offer dual water inlet lines for hot and cold water. For models that don’t, a restrictor has to be installed.

  • Central Unit

    Every tankless water heater features a central unit that varies from makers to makers and models to models. Some central units have temperature control knobs and LED screens to indicate the outgoing water temperature mounted on the central unit.

Things to Consider When Choosing the Right Tankless Water Heater

There are many factors that come into play when choosing a tankless water heater that fits your needs. Here are some tips to consider before buying one:

  • Your Hot Water Needs

    This is the first thing that you’re going to address after deciding that you need a tankless water heater. That of course will vary depending on your current water heating situation. For example, if you live in a home where there is an existing water heating system, then your prime concern for getting a tankless water heater is to use it as a complimentary unit.

    On the other hand, if you live in a small home with 2 to 5 people, then depending on how much how water you need, you should choose between water heaters that deliver 2 to 6 GPM. If you need to install a water heater for point of use applications, then again you will have to address how much hot water you need on a regular basis.

  • Climate

    Bear in mind that the long term efficiency of your water heater will depend a lot on the climatic region you live in. For example, if you live in a hotter part of the world, then you won’t have much trouble with the flow rate and consistency in water temperature, which will result in high energy efficiency.

    On the other hand, if you live in a colder part of the world, then the consistency in temperature and flow rate will be compromised along with energy efficiency. Hence, consider water heaters that are flexible in incoming water temperatures to make sure you don’t have troubles with it in the long term.

  • Electric or Gas

    In electric tankless water heaters, there are plug and play models and battery powered models. If you do a lot of moving around, then it is best that you get a battery powered model. If the electricity fluctuates in your area, then you can consider natural gas models. These models operate on natural gas and are more energy efficient than electric on-demand water heaters.

  • Point of Use

    While many brands may label their tankless water heaters as ideal for point of use applications, in practicality, they may not be able to deliver consistent water flow rates at consistent temperatures. If you are looking for a point of use water heater, then it is best that you start looking for water heaters that are designed specifically for that purpose.

    Flexible water heaters may be able to deliver performance on point of use applications and direct installation, but factors like climate, the incoming water flow rates, and the average use of hot water daily will come into play.

  • Temperature Control

    On-demand water heaters feature varying degrees of temperature control. Again, it depends on what your hot water needs and what limitations your climate brings. If you want a water heater that allows you to raise or decrease temperature by increments of 1 degree, then it will be ideal for both warm and cold climates. But a water heater that is not so flexible in temperature control will work ideally in one of the two climatic regions.


In retrospect, the ideal tankless water heater would be able to provide:

  • Continuous supply of hot water
  • High energy efficiency
  • Consistent flow rates in varying climates
  • Flexibility in use

The on-demand tankless water heater market has grown a lot over the past few years. What we have now is an extensive range of water heaters that are becoming readily affordable for the Average Joe. Before you go to buy a water heater (all considering all the factors) look up for the warranty. While some makers will provide 10 years warranty on the heat exchanger and 1 year warranty on other parts, others may have something better in store for you.

Another thing to consider is the reviews from users and experts on trusted websites. This will allow you to know any shortcomings in the water heater from hands-on experience of users. But at the end of the day, what you should look for is a water heater that meets all your hot water needs and reduces your energy bills down the road.

Further Reading on?Tankless Water Heaters