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

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Takagi Industrial Co. USA, Inc. is one of the leading manufacturers and marketers of tankless water heaters for residential and commercial purposes.

It was founded in 1952 in Japan and has since then expanded its reach to various other countries.

Takagi’s North American headquarters is at Irvine, CA. It was the first company to manufacture a tankless water heater with a thermal efficiency of 95%.

The Takagi T-KJr2-IN-NG is a gas tankless water heater that uses natural gas to provide hot water.

It is designed to be installed indoors. It has a moderate output flow rate and is capable of providing hot water for small whole-house applications in warmer climates.

Key Specifications Takagi T-KJr2-IN-NG

Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas The Takagi T-KJr2-IN-NG is an indoor-installation type, gas-fired tankless water heater. It has a maximum flow rate of 6.6 GPM which can supply water to an entire small residence in warm climates.

It comes with a power cord and remote control as its standard features which are usually additional accessories in other tankless water heaters.

The NOx emissions from this unit are very low and it also adheres to the lead-free standards.

Takagi has included several safety features in this gas tankless water heater and these include a built-in freeze protection system, a resettable hi-limit, a shut-down fuse for when it overheats, a flame sensor, and a temperature monitoring system.

Key Specs

Dimensions 20¼ in. H × 13¾ in. W × 7¾ in. D
Weight 38 pounds
Uniform Energy Factor 0.79
Service connections ¾ inches NPT
Minimum Gas consumption 19,500 BTU/h
Maximum Gas consumption 140,000 BTU/h
Minimum Water pressure 15 psi
Maximum Water pressure 150 psi
Recommended Water pressure 40 psi or above
Voltage 120 V AC
Ignition Electronic Ignition
Venting 4 in. category III stainless steel direct venting
Price Check Price on Amazon

Assembly / Installation

Although the product is small and easy to handle, the manufacturer recommends that a trained professional install the product.

The installation location has to be chosen carefully as the product is not to be installed in a pit or the attic.

The steps given in the installation manual must be carefully followed to avoid any damages. The local and state codes must not be ignored while installation.

The venting and electrical connections may require some changes from the existing configuration.

Installation can be done by the homeowner if he/she has the relevant skills required for the process. However, if any errors are to occur, the warranty may become void.


If the heater is being used for residential applications, the manufacturer provides a limited warranty for 15 on the heat exchanger.

For commercial applications, the heat exchanger is covered under warranty for 5 years. The warranty period is 5 years for all the other parts.

There are several factors that could void the warranty that include but are not limited to the quality of water, rough handling of the heat exchanger, installation not being done according to the manual, freezing of the water pipes, etc.

To avail warranty, the user should contact the place of purchase, write to Takagi, 500 Tennessee Waltz Parkway, Ashland City, TN 37015, call 1-877-737-2840, or visit the website www.takagi.com.

Consumer Comments

The Takagi T-KJr2-IN-NJ tankless water heater has received mostly favorable reviews from the customers. Most customers are satisfied with the amount of hot water it is capable to produce despite its compact size.

Not only is the heater small and light, but many users have also claimed that the heater is easy to install and it works perfectly when the installation is done properly.

The unit also shows no signs of slowing down while operating multiple showers.

Users have also responded to this product saying that it is a very cost-effective option for running two or three small fixtures at a time.

However, though not many, a few users have complained about the product not working as it should just after a few months of installation.

Also, for users who have installed the product by themselves, they were not able to claim warranty either.

Some users have also suggested that the product be sold with certain necessary accessories such as the shut-off valve and the mounting hardware.




  • The compactness of the heater allows the user to save a lot of space while installation.
  • It does not take up too much fuel and is greatly resourceful.
  • For the size of the unit, it has a generous flow rate of a maximum of 6.6 GPM.
  • Easy to install and maintain the unit.
  • It is relatively cost-effective compared to other gas tankless heaters.


  • It is not meant for large homes.
  • The operation of the heater is quite noisy.
  • The warranty may become void if the installation is done by the homeowner without proper certifications.



Takagi T-KJr2-IN-NG Indoor Tankless Water Heater, Natural Gas
  • 140,000 BTU. Voltage: AC 120V
  • 6.6 GPM max flow rate. Water connection location- bottom
  • 4-Inch category III stainless steel venting required

Recommended Accessories

Service valve kit

Service valve kit that allows the user to shut off the inlet and the outlet of the heater. It is necessary during draining and other maintenance procedure. Webstone 44443WPR 3/4-Inch IPS Isolator EXP E2 Tankless Water Heater Service Valve Kit with Clean Brass Construction


Pipe cover

Pipe cover to be attached to the bottom of the heater to cover the pipe connection entries.


Takagi TK-PCJr2 Pipe Cover for T-KJr2-IN and T-KJr2-OS from the T-Vent Collectio, N/A



Can this Tankless Water Heater share its Stack with a Furnace?

This vent stack of T-KJr2-IN is not meant to be shared with any other applications. It requires direct venting that is dedicated to this product only.

Does this unit Work in Higher Altitudes?

There are DIP switches present on the heater that allows the user to set the performance of the heater according to altitude. This can be set up to 6000 feet. Above this altitude, the user must contact the manufacturer for installing the product.

Can this System Handle Hard Water?

This heater is capable of handling water with hardness up to 7. Above this limit, it is recommended to install a water softener to avoid any damages to the heater.

Can I Install this Unit in the Attic of my House?

The manufacturer recommends that the unit not be installed in the attic due to problems that may arise due to improper electrical and plumbing connections. However, if installed carefully, this unit works well in the attic. The venting also becomes easier in the attic.

Our Recommendation

The Takagi T-KJr2-IN-NJ is a reliable gas tankless water heater that performs as described by the manufacturer. It is an energy-efficient and inexpensive product that can be used in a household of 2 to 3 people.

It is capable of running multiple fixtures at once and at the same time, provide an unlimited supply of hot water.

It is easy to install and maintain and also to monitor the unit because of the remote control accessory that comes with the unit.

This unit is a cost-effective and high-performance tankless water heater that is ideal for whole-house applications in small to medium-sized homes.


Last update on 2022-12-01 / Affiliate links / Images from Amazon Product Advertising API

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