Takagi T-K4-OS-NG Tankless Water Heater Outdoor review


Takagi has introduced a number of water heating appliances which are suitable for various applications. The T-K4-OS-NG model is a gas operated water heater designed for outdoor installation. It is one of the best models in the water heating product line introduced by the Chinese manufacturer. The appliance features a compact design but is still capable of fulfilling larger water heating requirements for an average household. It is the perfect heating solution for cold weathers. Unlike conventional storage water heaters, it takes up much less space yet offers a much more efficient heating solution.


More about the Takagi T-K4-OS-NG Tankless Water Heater Outdoor model is discussed below.

Functionality and Application

The appliance uses gas in order to function. It heats up water and is capable of delivering it to two to three bathrooms in a house. The water heater is capable of handling a large flow rate of up to 8.0 GPM. On the other hand, the minimum pressure required for the appliance to function is 15 PSI which can go up to a maximum of 150 PSI. The input of natural gas required to fuel the appliance ranges between 11,000 and 190,000 BTU/hour. There is also an electric ignition which requires an AC supply of 120 Volts.

Takagi T-K4-OS-NG Tankless Water Heater Outdoor provides sufficient quantity of heated up water for two to three bathrooms in a house. It is suitable for areas where a chilly weather is experienced. The outdoor unit heats up water instantly and provides a sufficient on-demand supply.

Convenient Installation Takagi T-K4-OS-NG

Although Takagi’s T-K4-OS-NG model of tankless water heater is capable of heating up large quantities of water, its overall size is small which makes convenient installation possible. Its compact body measures only 13.8 inches in width, 20.3 inches in height and 8.5 inches in depth. This means the appliance takes only a small installation space. It is suitable for limited space areas.

In order to install this model, a gas supply pipe in addition to a water inlet which supplies cold water. Moreover, outlet pipe connection is also needed in order to deliver the heated up water to the required locations. Unlike conventional gas water heaters, the T-K4-OS-NG Tankless Water Heater Outdoor model by Takagi does not require additional vent caps or category III venting. Instead, it comes with its own inbuilt venting system. This further makes the installation more convenient and saves both time and money.

Safety Features

Safety is of a higher concern for indoor water heating units. However, it is equally important for systems installed outdoors since the pressure of gas, a high temperature or any malfunctioning component may lead to potential dangers. Takagi T-K4-OS-NG model is fully packed with safety features. These are discussed below.

  • The appliance accompanies inbuilt anti-freezing protection. This means it can be installed even in the coldest areas without the fear of freezing which may lead to malfunction of the appliance. This saves users from the hassle of maintenance and the associated charges.
  • Overheating is prevented by the heater’s thermostatic function. It regulates and maintains the preset temperatures. Users have to the option to choose from four fixed presets – 113F, 122F, 131F and 140F.
  • The water heater features a surge protector for its electrical ignition. This provides protection to the appliance in case of voltage fluctuations.

Efficient Function

Traditional water heating systems often lead to wastage in terms of fuel, power as well as water. In addition, polluting emissions also harm the environment. On the other hand, Takagi’s outdoor water heating model T-K4-OS-NG ensures efficiency and is also environment friendly. It cuts down fuel and power wastage through its thermostatic function. Moreover, with an energy factor of 0.82, this appliance is favorable for the environment.

amazon button