A review of popular Takagi water heaters, including ultra-efficient and low NOx Takagi T-H3 models. Explore the most advanced Takagi tankless models with condensing technology, reaching high energy efficiency of over 95%. Check out the best models and features to look for, from small to large homes, using one or multiple fixtures.
Takagi water heaters are equipped with many advanced and advantageous features ensuring high performance, efficiency, better user experience, comfort, and significant savings. Some of the top features are:
Takagi offers several models with tankless technology designed for residential and commercial applications, where the most advanced models include condensing technology, integrated digital controls, “green” combustion, and efficient operation.
For easier selection, we will group all the tankless models into three categories, so depending on your home size, you can select one either for small, medium, or large-size homes.
To choose a suitable Takagi model, you have to know what size to look for.To properly size the heater, consider the following factors; peak flow requirements, temperature rise (the difference between outgoing and incoming water temperature), and types of applications.
To calculate the peak flow requirements or how much hot water you need at one time, use the chart below. See how many applications are to be used simultaneously and add those numbers to calculate the total sum of the water flow.
Example: If running three applications simultaneously: 2 showers (2.5 GPM) and a washing machine (2 GPM) (2x2.5+2=7 GPM), the total flow rate is 7 GPM. To get enough hot water, choose a model from Takagi T-H3/540P series.
Below is the table with the available Takagi models, water flow, and a number of fixtures it can supply, and for two regions – warmer with the temperature of the incoming water of 70 F and colder – with the temperature of water 50 F.
|# of showers in
|# of showers in
Takagi T-KJr2-IN and T-KJr2-OS models are the smallest tankless water heaters that use only one heat exchanger, making them non-condensing. These are recommended for homes with one to two bathrooms, apartments, cottages, and condos, and indoor (T-KJr2-IN) and outdoor (T-KJr2-OS) installations.
Takagi T-KJr2 models are designed for an efficient and cost-effective way of residential water heating and can be combined with a radiant floor or baseboard heating. Takagi T-KJr2-IN can be converted into direct vent models for use in confined areas with the appropriate venting kit. The temperature controllers are provided for convenient use. The heaters use a two-pipe vent system for an efficient and low NOx gas emission to the outside atmosphere.
TK-110C-NI is a non-condensing unit designed for indoor use only, and it comes with the one-pipe concentric vent option. Small size, great for small houses and apartments. This is an ultra-low NOx model that has the temperature controller built in.
An indoor model TK-110U-I also comes with an integrated temperature controller provided for an outdoor model TK-110U-E. The model has a small size, so it is great for small houses and apartments. Ultra-low NOx gas emission. Non-condensing.
Similar model: Rinnai RL75
Takagi T-K4-IN and T-K4-OS are non-condensing, tankless water heaters designed as indoor and outdoor models with the water flow capacity and energy efficiency sufficient for heating water in homes with up to 3 showers - working simultaneously. The remote control is not built-in but is provided as the standard feature. The venting system of the indoor model uses the two-pipe system. Low NOx emission.
TK-310C-NI is a non-condensing indoor unit that comes with a concentric venting system for easier installation. It meets the ultra-low gas emission requirements. It comes with a built-in temperature controller.
The 310U series offers two models; an indoor TK-310U-I that uses the two-pipe venting system and an outdoor TK-310U-E model, which is vent-less. An indoor model comes with the integrated temperature controller, while it is provided with the outdoor unit. These are ultra-low NOx models.
Takagi T-D2 water heaters are designed for residential and light commercial applications and indoor and outdoor installation. Up to 4 heaters can be connected to one system using the Easy-Link communication cable. They utilize the commercial-grade heat exchanger.
Takagi TK-510C-NI comes with the concentric vent option making installation much easier. It is available only as an indoor model. Due to its powerful burner and commercial-grade heat exchanger, it is recommended for heavy hot water use. It meets ultra-low NOx requirements.
The model can be used in homes and commercial applications. It is designed for residential water heating, combination space heating, and recirculation systems. With the Easy-Link communication cable, up to 4 units can be connected, while the Multi-Unit controller allows up to 20 units. The temperature controller is built-in.
510U series comes with almost the same features as the above 510C series (including the Easy-Link and Multi-Unit systems), with the difference that the indoor model TK-510U-I uses the two-pipe system. There is also an outdoor type - TK-510U-E, designed for homeowners who prefer outdoor installation.
Takagi water heaters from the H3M series have the lowest water flow rate, while the H3 models are the most powerful and have the highest hot water delivery rate.
All the models from Takagi H3 series are Ultra-low models and Energy Star compliant. Indoor models come with the two-pipe vent system and integrated temperature controller, while the outdoor models are ventless and come with a separate controller. Only the T-H3-DV-N and T-H3-OS-N use an Easy-Link or Multi-Unit controller to connect more units into one system and provide more hot water.
Takagi water heaters TK-540P-NIH and TK-540P-NEH are tankless and condensing water heaters that can provide instant hot water. How? The series integrates a recirculation pump and a dedicated recirculation line.
A temperature and pump controller are integrated into indoor models and provided with the outdoor units. These units are also ultra-low NOx compliant and can use Easy-Link for more hot water delivery.
Similar model: Rinnai RUC98
While there are many tankless models to choose from, Takagi T-H3-DV is one you should consider buying. Takagi T-H3-DV is a tankless water heater with condensing technology designed for heavy usage in a residential home.
There are several notable features behind the modern look, such as cutting-edge electronics and a powerful gas burner. The model can reach a high 199,000 BTU, so the water is heated with the ultra-high energy efficiency of 0.95 and delivered to a maximum of five fixtures with up to 10 GPM rates.
Tankless water heaters, such as Takagi, do not store hot water as the conventional tank type. Tankless models heat water on demand when it is passing through one or two heat exchangers. Those models with two heat exchangers are called condensing. And they are the biggest energy savers. This is important because up to 25% of the home’s annual energy use goes on water heating.
Another great advantage, except on-demand heating, is the unlimited supply of hot water. The advanced models are controlled by the built-in computer, allowing improved temperature control, accuracy, enhanced safety, convenience, and comfort. Also, reliable and durable operation is featured.
Takagi water heaters are compact and lightweight that comes with the size of a small suitcase, allowing easy handling and installation. The wall mount, long vents, and flexibility in the design ensure unit installation almost anywhere inside and outside the house.
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Takagi Industrial Co. is one of the four popular Japanese manufacturers of tankless water heaters sold in the US. The headquarters is in Japan, and Takagi has been designing and producing water heating appliances since 1952.
According to the manufacturer, Takagi water heaters are the first units with a continuous water supply and on-demand heating that entered the North American region.
Also, Takagi is among the first ones who offered a model, T-H1, with an ultra-high thermal efficiency of close to 95%.