Takagi Tankless Water Heater Reviews – Picking The Best One For Your Needs

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Takagi T-KJr2-IN-NG Indoor Tankless Water Heater

Key Features:

  • Can be converted into a direct-vent unit
  • 140,000 BTU. Voltage: AC 120V
  • 6.6 GPM max flow rate. 
  • Inlet, outlet thermistors for constant temperature monitoring
  • Energy factor of 0.81-0.83


You can read up on water conservation and look for tips on reducing the amount that you use at home, or you can invest in a Takagi tankless hot water heater. The hot-water heaters made by this company come with built-in connections for easy installation, and some feature digital controls too.

One thing to keep in mind when shopping for one is that you need to choose between those designed for use with propane lines and those that will work with natural gas. Takagi also makes hot-water heaters meant for use inside and those that you can install outside.

The absolutely best tankless water heater that you can buy today is the Takagi T-H3-DV-N Condensing High Efficiency Natural Gas Indoor Tankless Water Heater, which can heat up to 10 gallons per minute. Though the flow rate and maximum heat will vary based on weather conditions and the ambient temperature, it can usually supply enough hot water for up to three or four bathrooms at the same time. As an indoor hot-water heater, they guarantees that it will meet emissions standards and that it’s safe for use in your home because it vents the gas outside.

Top 10 Best Takagi Tankless Water Heater Review

1. Takagi T-H3M-DV-N Indoor Tankless Water Heater

Takagi T-KJr2-IN-NG Indoor Tankless Water Heater

Takagi T-H3M Tankless Water Heater has been in the market for 60 years and has been delivering intuitive water solutions for commercial and residential purposes. Takagi water heaters are known for their diversity and quality, providing an ideal hot water solution.

The T-H3M-DV-N is one of Takagi’s premium line of heaters. Condensing Technology adds to the factor of Uniform Energy when paired with Ultra-Low NOx makes it one of the most efficient water heaters in the market. If you have an existing gas line, you would not need to change it as it comes with a 5″ gas line.

One of the key features that this water heater has is its primary heat exchanger made from high-grade copper alloy. It allows a transfer of heat that is better than stainless steel. The H3M is available with a list of standard safety features that include an internal freeze protection system, over-heat cutoff fuse, water temperature safety controls, and an air-fuel ratio sensor.

The primary exchanger is made from copper and is resilient. It also has a backup that’s stainless steel to protect against corrosion.

2. Takagi T-H3-DV-N Natural Gas Indoor Tankless Water Heater

If you love everything about the number one model from this brand but have natural gas lines instead of a propane line in your home, this T-H3-DV-N Condensing High Efficiency Natural Gas Indoor will appeal to you because it comes with all the same features but will work with natural gas.

Shower heads usually have a maximum flow rating of around three gallons of  H2O per minute or less, and as this heater can heat up to 10 gallons of H2Oper minute, you’ll have more than enough hot water for taking a long and hot shower. This higher rating also allows two or more people to use other showers or sinks in the house at the same time without running out.

Though you’ll likely love the almost endless supply of hot-water that this model offers, you’ll also love that it offers hot-water on demand and that it will give you access to hot-water as soon as you press the power button and turn the knob on your sink or tub. It uses a computerized system to give it the power required and gets rid of the pesky pilot lights used by traditional models. It also meets low emissions standards.

The T-H3 is a great model that will work in most homes, including those located in cooler regions as well as those in warmer areas. It operates so quickly that even if the groundwater outside is cold, it can still heat the supply for a maximum of three bathrooms.

When you use the T-H3 in a warmer climate, it will supply hot H2O to your kitchen and multiple bathrooms on demand.

3. Takagi T-H3S-OS-N Condensing High-Efficiency Natural Gas Outdoor Tankless Water Heater

Takagi T-H3S is a tankless heater with unmatched diversity and quality, giving hot water for your daily requirements. It is a part of the efficient line of condensing water heaters.

The latest water heating condensing technology delivers the highest standards in the market. It helps you to save on time and money.

The T-H3S qualifies as the Low NOx standards that are stringent. It also includes the air quality districts and SCAQMD that aim to limit pollution in the southwest of the United States.

The primary exchanger is commercial-grade copper that is resilient to corrosion. The backup is stainless steel also keeps away corrosion. The tank has a list of safety features: internal freeze protection system, over-heat cutoff fuse, water temperature safety controls, and an air-fuel ratio sensor.

The condensing technology gives the H3S a 0.95 Uniform Energy Factor making it one of the best heaters in the market. The heater comes with a remote control that helps you to control the temperature on the heater.

The heater has a built-in temperature control with advanced diagnostics for more straightforward troubleshooting.

4. Takagi T-H3S-DV-N Natural Gas Indoor Tankless Water Heater

The only real difference between this T-H3S-DV-N Condensing High Efficiency Natural Gas Indoor and the other model we ranked as the best is that it heats a smaller amount of H2O every minute, but depending on the size of your home, you may find that the eight gallons of hot H2O it can provide every 60 seconds is more than enough for your needs.

With its on demand design, you’ll never find yourself standing around and waiting either because the heater will provide instant access to hot water that you can use on the spot. As an ultra low emissions model, you’ll also love knowing that it will work with any vents and keep the natural gas used from possibly harming your family.

Installing this model is so easy that you might decide to do it on your own. It comes with metal connections at the top that hook up to the pipes to allow H2O to enter the heater and exit back and into your plumbing system. The company not only includes installation instructions inside the box, but the manufacturer also has a toll-free number that you can call with any questions you have.

With a 180,000 BTU rating, it provides the hot-water that you need for cleaning around your house and for personal care. They recommends using this model in both warmer and cooler climates because it can supply for two bathrooms in colder climates and three bathrooms in warmer climates. The ambient temperature in your home, the air temperature outside and the groundwater temperature will all play a key role in how hot the water in your home will get.

5. TAKAGI TH3OSNG Tankless Water Heater

The T-H3 is a water heater without a tank, making it easier to install in tight spaces without it taking up that extra space. This heater is ideal for commercial and residential use. It meets the NXo Ultra-Low regulations.

The heater has a thermistor on the inlet and outlet to help in monitoring the temperature. It is ideal for radiant heating applications and light residential use. This heater is certified to operate at up to 10,000 FEET altitude.

The number of shower baths this heater can handle depends upon the temperature of the groundwater. Takagi considers its customers as a top priority and offers customer assistance for a variety of services.

The water heater is manufactured in Japan, and its manufacturer believes in their product and provides a 15 years warranty on the heat exchanger. This warranty applies to the exchanger made of copper and stainless steel.

They also offer a five-year warranty on parts and one year on labor. So now, you can purchase this heater with no stress at all.

The Takagi water heaters are gas models and advise for safety reasons to install the heater through a licensed plumber and electrician. The warranty is valid only if a licensed plumber installs the heater. It comes with a user-friendly manual and easily installed by a plumber.

6. Takagi T-H3J-DV-N Condensing High-Efficiency Natural Gas Indoor Tankless Water Heater

With over 60 years of innovative contributions, Takagi is one of the best when it comes to tankless water heaters. The heater has a sleek design that makes it easy to install, even in tight spaces.

The H3J offers Ultra-Low NOx Technology that allows you to use a 3: PVC venting, it also has a 0″clearance for combustibles. The primary heating exchanger is copper, and the indoor units are certified to operate at an altitude of up to 10,000ft.

It can handle several shower units, but the exact number depends on the temperature of the groundwater. It has a gas input of 160,000 BTU. The H3J can heat enough water to supply two baths in the summer and 1.5 bathrooms in winter.

The copper exchanger is 25 times better than the stainless steel ones. The backup exchanger used 316L stainless steel for better resistance from corrosion. It has a variety of safety features like troubleshooting diagnostic codes, surge protection, overheat, and freeze.

The manufacturer offers a 15-years limited warranty on the exchangers, a residential five-year limited warranty on parts, and one-year on labor.

7. Takagi TK-510C-NI 199,000 BTU Concentric Vent Indoor Non-Condensing Tankless Water Heater

The TK-510 is a fully modulating, tankless, gas-fired water heater. The heater has a power vent flue and sealed combustion. This heater is clubbed with a recirculation system and water storage tanks for convenience. The TK-510 complies with the Ultra-Low NOx regulations.

The heater is easily convertible from natural gas to liquid propane. The primary heat exchanger is made from commercial-grade copper, while the secondary heat exchanger is stainless steel. Both the exchanges can resist corrosion, prolonging the durability of the heater.

The Tk-510 has a centric vent and is NSF certified for commercial applications. The TK-510 is easily linked to multiple units using a Multi-Unit controller. It has a variety of safety features like troubleshooting diagnostic codes, surge protection, overheat, and freeze.

The product is manufactured in Japan and is built for performance and durability. The manufacturer offers a 15-year warranty on heat exchangers, a five-year warranty on parts, and a one-year labor warranty. It also comes enclosed with a user manual that explains the steps of installations. It makes it simple for the licensed plumber.

The warranty is applicable only if the installation was carried out by a licensed plumber and electrician. For further assistance, you can reach out to the customer care number made available.

8. Takagi T-H2S-OSLP Outdoor Condensing Tankless Water Heater 

Takagi has been in the market for over 60 years, meeting client requirements with its innovative water heating line. The H2S is one of its top of the line water heaters.

The heater doesn’t have a tank, and its sleek design makes it easy to install in tight spaces. It is a high-efficient condensing model. It complies with the low emission Ultra-Low NOx. The heater has an Air-fuel ratio sensor.

The heater can produce up to 8.0 gallons per minute. It also has a gas input of 180,000 BTU. The H2S is for residential purposes only. The heater is one of the most energy-saving units – it takes up to 0.90EF in the tankless water heater industry. It has a cutoff fuse to avoid overheating.

The heater provides an endless and efficient supply of hot water to meet your daily requirements. The product is made in Japan and comes with a 15-year limited warranty on exchangers, five-year limited on parts, and one-year limited on labor. The warranty is applicable only if a licensed plumber and electrician install the heater. The primary exchanger is copper, and the backup exchanger is stainless steel – both are corrosion resistant.

9. Takagi TH3JDVLP Tankless Water Heater

The T-H3J is a dynamic top of the line water heater. It is one of Takagi’s highest performing units with 6.6 gallons of water per minute.

The key feature is the condensing technology, 0.95 uniform energy factors, and when paired with an Ultra-Low NOx, this heater is one of the best heaters on shelves today. The heater is made from premium quality material.

The primary exchanger is made from commercial-grade copper, and the secondary exchanger is made from stainless steel. Both the exchangers are incredibly resilient to any sort of corrosion.

For many of us who are safety conscious, the unit comes with an extensive list of computerized and standard safety features – internal freeze protection system, over-heat cutoff fuse, water temperature safety controls, and an air-fuel ratio sensor.

The T-H3J comes with advanced diagnostics as well as built-in temperature control. This feature can help you save up on your money and help with troubleshooting too.

This unit is for residential use like space heating and recirculation system. This unit is suitable for all your business and household water solutions.

10. Takagi TH3JDVLP Tankless Water Heater, 6.6-Gallon per Minute

If you want a larger model that provides enough hot-water for multiple bathrooms and your kitchen, the T-H3-DV-P Condensing High Efficiency is the best option from this manufacturer.

Designed for installing indoors, it has a higher efficiency than other models, which lets you know that it will help you save on the money you spend each month for hot-water. It uses modern parts that eliminate the need for lighting a pilot light and keeping that pilot light on too.

With a standard mode that has its own tank, you need to worry about finding room for it in your home and about routine maintenance, but it requires much less in the way of maintenance.

The screen on the front is easy to view, even in the dark, and the buttons nearby make it easy to access the main menu, run a diagnostic scan of the heater or simply adjust the temperature based on your preferences or the preferences of someone else in your family. It also meets the standards required of all low emissions models.

One thing you may not realize about how the unit works is that these heaters heavily rely on the temperature of the groundwater outside and that when the groundwater is warmer, it will act faster and send supply through your pipes faster too.

When you use this in a cooler climate region like the Midwest, it can provide enough supply up to three bathrooms. If you use the heater in a warmer climate that has warmer groundwater temps, you’ll find that it can supply up to four bathrooms as well as a kitchen.

Which One is The Winner?

Takagi T-KJr2-IN-NG Indoor Tankless Water Heater

The Takagi T-H3M-DV-N Indoor Tankless Water Heater, Natural Gas really is the best choice from Takagi because it can cut down on H2O waste and saving water bills too. Designed to meet emissions standards, it can also heat water for up to four bathrooms.