Best Tankless Water Heater

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Rinnai, Noritz, Paloma, Bosch, Takagi... which one is the best tankless water heater? Selection and review of the top on-demand and non-condensing models in North America.

This review covers the best tankless hot water heaters from several manufacturers present in North America. All of the heaters are gas powered using either natural or propane gas, Energy Star compliant, have the most advanced features and quality materials, and are designed to provide the highest water flow, for high demanding homes. 

If looking for the best condensing gas heaters and the review of its features, check out this review.

Best tankless for residential use

How to select the best tankless

AO Smith TanklessThe best tankless water heater is made of the quality and strong materials so it can last longer and provide reliable water heating for many years. One of the main elements is the heat exchanger, which, because of the high thermal stress, has to be made of the commercial grade copper or stainless steel, so it doesn't rust, can last long and perform well.

The best unit is the one which is also versatile, have flexible venting system and can be installed anywhere inside your home.

The smart technology is must today, so models equipped with the diagnostic system are recommended as it provides an easy troubleshooting, monitoring and control of all the parameters.

The top models are listed below, and try to get the brand where the manufacturer provides decent service network, the models come with a long warranty and have the spare parts available anytime.

The Best Rinnai Tankless Water Heater

rinnai rl94 series

The best tankless water heater from Rinnai, a Japanese manufacturer, is coming from the RL94 series. The indoor model RL94i is, thanks to the maximum power of 199,000 Btu, was designed to provide high 9.4 gallons per minute, which makes it ideal for providing enough hot water for up to five applications, working simultaneously.

It's high efficient and environment-friendly burner helps this Rinnai unit to get Energy Star approval, deliver up to 40% in savings while emitting less NOx gases.

Low power of 9,900 Btu allows Rinnai to operate with lower water flow (0.4 gpm), which is enough where the smaller amount of hot water is needed.

The compact and lightweight design of 50 pounds allows easy wall mounting, which saves precious floor space, and its concentric venting system brings lots of flexibility in the installation, so the flue gases and air intake are safe and reliable.

Temperature monitoring and settings change are very convenient as the controller is a standard feature, and is built-in while providing the easy troubleshooting through the diagnostic code system.

The Best Noritz

noritz nr98

The best tankless water heater, non-condensing, from Noritz is the model NR98-SV. Noritz NR98-SV is a gas model that is designed for the indoor use and with the right kit, easily transformed for the outdoor use.

With the maximum continuous water flow of 9.8 gallons per minute, NR98-SV is perfect for homes with up to four fixtures working at the same time. The commercial-grade heat exchanger, where cold water is heated, is thicker and more durable than those installed in Rinnai, Paloma or Takagi tankless models.

On the other side, a minimum flow of 0.5 GPM is still good enough for heaters activation and when the smaller amount of hot water is needed. Fully modulating gas blower automatically adjusts its power to meet the set temperature and based on the water flow. Temperature fluctuations, which are common in most heaters, is reduced thanks to the dual flame burner. For those homes that need even more hot water, Quick Connect cable allows connection of the two identical units into one system.

The Best Paloma

paloma ph2-28

The best tankless water heater, gas-powered and non-condensing, from Paloma is model PH2-28RDVSN, coming from 9.5 or PH2-28 series, a high-volume series can provide a maximum of 9.5 gallons per minute and enough hot water for two-three bath-homes.

Environment friendly burner is capable of heating the water with the thermal efficiency of 84%, where 11,000 Btu can provide enough energy for its minimum of 0.4 GPM while the power of 199,900 Btu efficiently heats 9.5 gallons of hot water per minute. For double performance, DUOnex cable is used which connects two identical units into one system.

The Paloma exclusive feature an ICAD or Incomplete Combustion Avoidance Device is used to optimize gas combustion and shut the unit off in a case of the increased level of carbon monoxide. Another cool feature, an Overheat Limiter Wrap is the plastic film that is wrapped around the heat exchanger so in a case of the overheating it shuts down the unit.

As with the previous two models, an extensive diagnostic and error display is used on the remote control for easy troubleshooting and temperature control.

The Best Takagi

takagi tk3

T-K3 is the best tankless water heater from Takagi, designed for residential water heating, mainly. Built as the most powerful and versatile heater, T-K3 works as the outdoor model with an option to convert the heater into the direct vent model and for an indoor use.

Its power goes from 11,000 Btu to high 199,000 Btu and with the modulating gas burner, it is heating and delivering water from low 0.5 GPM to high 7 GPM. For high demanding applications, it uses the cable link to connect two units into one system...more

The Best Bosch

bosch c 940 es

Bosch Therm C 940 ES is the high capacity and high efficient tankless water heater, which is designed to provide 9.4 gallons per minute of hot water for high demanding application. If more hot water is needed, an intelligent cascading will get up to 24 units connected into one system, operated from a controller.

Its direct-vent sealed combustion, and dual fan technology allows an indoor installation almost anywhere within your home. With the correct kit, C 940 ES model can also be converted for the outdoor installation.

Modulating premix burner and constant gas/air ration, combined with the modulating water valve, improves the gas combustion and temperature stability.

It is used not only in residential water heating, but solar thermal and recirculation applications. Great 15-year warranty makes this Bosch tankless water heater a good buy.

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So which one, from the above five brands is the best tankless water heater? I have reviewed every model from these manufacturers, and the above list represents the best gas water heaters from these manufacturers, excluding condensing models, which are reviewed here.

From the above heaters, I would select either Noritz or Rinnai, but the decision is yours.

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