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



Takagi has, over the years, distinguished itself from its competitors with their sleek design and comprehensive features in tankless water heaters. The Takagi T-KJr2-IN-NG is no exception to that, and is marketed as the smallest unit from their line-up. The T-KJr2 comes in two different specs, the IN-NG model for indoor use, whereas the OS-NG model for outdoors.

The Takagi T-KJr2-IN-NG indoor tankless water heater is definitely a masterstroke as it is one of the highest rated tankless water heaters available today. Since 2010, the T-KJr2-IN-NG has made many loyal customers and delivers what matters, performance and energy efficiency. Take a look at what makes the Takagi T-KJr2-IN-NG indoor tankless water heater a must buy for your home or workplace.

Important Features and Specs

The Takagi T-KJr2-IN-NG indoor tankless water heater is one of the most consistent water heaters when it comes to performance. It delivers 6.6 gallons of hot water in a minute, which makes it ideal for homes, apartments, offices, and other indoor areas. It’s a natural gas indoor water heater that can easily be installed on a 3/4 inch gas line. As mentioned before, it is the smallest water heater in the Takagi line, which makes it highly portable and convenient to install just about anywhere.

The Takagi T-KJr2-IN-NG indoor tankless water heater has a gas input of up to 140,000 BTU per hour, which means that it can easily meet the hot water demands of an average sized home with two to three bathrooms. Speaking in retrospect, the Takagi T-KJr2-IN-NG can deliver the same water heating performance as a 40 gallon tank water heater. It can easily be mounted on a wall or under a sink, and can deliver up to 200 gallons of hot water on demand in an hour.

The Takagi T-KJr2-IN-NG is a lightweight tankless water heater that only weighs 38 pounds and has measurements of 6.7 x 13.8 x 20.3 inches. While it is larger in size than many compact tankless water heaters, not many offer the same water heating capacity in that size as Takagi T-KJr2-IN-NG does. It features thermostats in both the gas inlets and water outlet to allow consistent temperature overtime.

Rated with an Energy factor of 0.81 – 0.83, the Takagi T-KJr2-IN-NG indoor tankless water heater is as energy efficient as a natural gas water heater can get. It can support radiant floor heating applications as well, which makes it an ideal multipurpose water heater.

As far as installation goes, while it is easy, we recommend you hire professional as improper installation can lead to safety concerns. That being said, the Takagi T-KJr2-IN-NG indoor tankless water heater does have safety features like an Air Fuel Ratio Sensor (AFR), Water and Exhaust Temperature Safety Control, and an internal freeze protection system. It takes less than an hour to get the water heater installed, and from then on, it’s ready to use. It comes with a 10 year limited warranty on the heat exchanger, and a 5 year warranty on parts.


  • One of the best indoor tankless water heaters in terms of heating capacity.
  • Compact design and lightweight body.
  • Uses natural gas – highly energy efficient.
  • Perfect for average sized homes.
  • Safety features ensure no gas leaks occur.


  • Needs to be installed properly, otherwise it poses a hazard.
  • Not practical for small homes as it is quite expensive.
  • Gas fluctuations may affect hot water flow rate.

Who Should Buy

The Takagi T-KJr2-IN-NG indoor tankless water heater is one of the hottest water heaters in the market, and reviews suggest that most buyers are average sized families with 3 to 5 people living in a household. When a water heater delivers up to 6.6 gallons of hot water per minute, then it’s bound to be useful for families.

If you live in a large home with more than four people, then the Takagi T-KJr2-IN-NG would be ideal as a complimentary unit to your existing water heating system. It only requires maintenance once a year and has been renowned as a durable model by users. It is ideal for countries with mild to chill climate, but works well in colder weathers as well. If the gas flow rate is consistent in your area and you’re looking for a long term solution to your water heating needs, then the T-KJr2 is just what you need.


The Takagi T-KJr2-IN-NG indoor tankless water heater, while expensive, can be a cost effective solution to your water heating problems in the long term. It has everything you need from a performance oriented water heater that helps reduce your monthly energy bills. The customer reviews have been positive and it’s one of the highest rated indoor tankless water heaters on Amazon. If you are looking for a water heater that can turn out to be a delightful investment down the road, invest in the Takagi T-KJr2-IN-NG.