Takagi – T-K4-OS NG Natural Gas, Outdoor 8 GPM| Review

Takagi -T- K4-OS- NG is 38 pounds outdoor ankles heater powered by natural gas. This heater has an impressive flow rate of 8.0 GPM with BTU of 11,000- 190,000.

Takagi – K4-OS-NG became available in the market in September 13, 2013, and currently available for shipping to select countries outside the US but also including the US. Its dimension is 8.0 x 13.8 x 20.3 inches very compact and highly efficient.

This unit comes in color white, energy star and specifically designed for outside installation. It can be installed indoor but a DV kit is needed for the installation. It is a perfect for small sizes family with 1 -1/2 bathroom house. The unit is ideal for families where the demand for hot water is not high. It can only supply water to a dish washer and shower simultaneously.

Features and Benefits of Takagi-T-K4-OS-NG

No venting required

This unit requires no venting. It has an in built power venting system. This is responsible for the humming sound Takagi’s unit emits when the heater is off. This sound is as a result of the built in power venting system which vents the unit of leftover fumes and also cleans the burner.

There is no need of any additional category 3 venting or vent caps. The installation process is easy and fast. The absence of these venting accessories make the cost of acquiring and installing a Takagi -T-K4-OS- NG very pocket friendly.

Company Warranty

The unit comes with 5 year warranty on heat exchanger, 3 year parts and 1 year labor for residential application while commercial application gets a warranty of 3 years on heat exchanger, 1 year part and 1 year labor. The warranty is valid as long as you use a licensed technician for the installation the unit.

Inlet and outlet thermostats

This allows for constant temperature monitoring and works in two ways. It monitors the temperature of the incoming water from the water source and also the temperature of water flowing from the outlet faucet. This feature ensures that your hot water flows at consistent temperature and a plus over the traditional tank water system with its constant temperature fluctuations.

Built in freezing protection

Takagi- T –K4-OS-NG being an outdoor installation water heater is affected by climatic changes especially during winter. Having a built- in- anti freezing protection insulates against cold, ensuring you continue to use your heater to your hearts content even under extreme cold weather. No temperature fluctuation as it comes with an adjustable temperature controller which allows you set the temperature to suit climatic changes. The good thing about this water heater is that you have up to ten temperature range to choose from.


The only snag with Takagi-T-K4-OS-NG is that it needs a proper licensed technician to install the unit. And this does not come cheap. Also since it is designed for outside installation the unit should be shielded from rain as it can causes damage to the unit cutting short your thrill over the unit.

Review Summary

Going by the positive customers review on Takagi-T-K4-OS-NG, the unit is recommended to small sized family looking for a compact unit that is at the same time highly efficient in delivery hot water on demand.

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