The Best Tankless Water Heater

Review of the top 3 gas-powered on demand water heaters

Finding the best tankless water heater for your home? So, which one to select: Rinnai, Noritz, Takagi, Navien, Paloma, Rheem, or Bosch? We find, review and select the best tankless hot water heaters for you.

The best tankless hot water heaters are condensing units that are high efficient and qualified for Energy Star. What's great about condensing water heaters is their ability to use the heat from the flue that would otherwise be lost.

The temperature of the flue gases significantly decreases so instead of using expensive vents, cheaper PVC is utilized. The best models are designed with many innovative features and quality elements, which ensure energy savings, better performance, reliability, long life and low emission of the greenhouse gases.

Selecting the best tankless water heater


The best tankless water heater lasts over 20 years and most of its components are replaceable and recyclable... which is not the case with the storage tanks. The best model is equipped with the quality components which are strong, reliable and long lasting. When comparing unit's features (elements) look for the "commercial grade" or "professional" as such elements guarantee the quality and put one heater above the other.

The perfect example is Japanese manufacturer of tankless water heaters Noritz with its commercial grade heat exchanger and gas burner. One of their top models is reviewed below which shows several powerful features.

The most important elements on one water heater are the gas burner and heat exchanger. The best tankless unit has both elements made of the high grade stainless steel which can resist the increased thermal stress, perform and last longer than those made of cheap materials.

The best models have eco-friendly burners, which burn the gas efficiently while emitting less CO and NOx gases for cleaner and greener environment.


The best tankless water heater is also versatile unit. It can be used for water heating, space heating, radiant heating, as the single unit or combined with more for higher hot water demand.

Most of these on-demand WHs are factory set to use natural gas. The best tankless heater uses both fuels, and the conversion kit is included in the package so you can always convert the heater to use the propane gas.

Advanced features

Advanced electronics as the brain of the heater is a major element that ensures that everything works perfectly. The best tankless water heater is equipped with such a small computer so it can collect all the necessary information from its sensors and it ensures that the heating process is smooth and efficient. Intelligent diagnostic systems in top models are "mandatory" as they deal with problems and troubleshooting.

Efficient venting

The best tankless water heater uses the high performing concentric vent. These vent systems should provide flexible installation, which allows heaters to be mounted almost anywhere. They are designed to provide zero clearance venting so the vent pipe is cool to touch. No need for the expensive, stainless steel vents, cheaper PVC pipe is what you will need.

emergency plumber

Who makes the best tankless hot water heaters?

I have found several top gas powered tankless hot water heaters in US and Canada that can be called the best. All these "the best" models are using condensing technology and incorporate the most advanced features for efficient potable water heating.

Noritz NCC199-SV

noritz NCC199-SV is one of the best tankless water heatersNoritz manufacturer is one of them. The best tankless water heater from Noritz is coming from NCC199 (N-0841MC) series.

Noritz NCC199-SV is the most efficient tankless unit, Energy Star qualified that is designed to provide over 93% energy efficiency without sacrificing the hot water output.

Noritz tankless models are equipped with the durable dual heat exchanger, combination of stainless steel and copper and stainless steel dual flame burner, which significantly reduces temperature fluctuation while maximizing the output.

Versatility is what is great about this unit. Most of the components are commercially grade, and the exterior casing is made of a corrosion-free stainless steel, so Noritz NCC199-SV can be used for both residential and commercial applications. It can be installed indoor or outdoor, vented horizontally or vertically, and is available in natural gas and propane LP models. The unit is recirculation compatible, has the multi system to link up to 24 units - operated by one single controller, and with the combi-system set-up can be used for both potable water heating and space heating.

Rinnai RC98i

rinnai RC98iThe best tankless water heater from Rinnai comes from the "Ultra" series, the series that features Ultra Efficient Condensing Technology.

Rinnai RC98i model is built as the condensing tankless water heater for larger homes with high hot water demand. With the maximum gas input of 199,900 Btus this unit provides thermal efficiency of up to 96% making it high efficient and Energy Star qualified.

Rinnai RC98i is equipped with the two innovative heat exchangers so more heat is captured (including the heat from the flue) and transferred to the water. In 2010 in "Builder's Magazine", Rinnai was chosen as the best tankless water heater for its efficiency and quality.

Navien CR-240A

navien condensing unitThe best tankless water heater from Navien, CR-240A, offers the Ultra Condensing Efficiency and the Best Value for greener environment and great savings for you. It has one of the highest energy factors in the industry, 0.98 and great 11 GPM flow rate.

Navien condensing water heater is equipped with two stainless steel heat exchangers, much more durable than copper-made found in cheaper models. Navien incorporates unique features such as the Eco Pre-mixed Burner that has three phases for optimal gas combustion and significantly reduction of NOx gases. See the price here.

Navien CR-240A is using two microprocessors that provide better heating control, maintain the uniform hot water temperature and enhance the safety. Air and Gas Pressure Sensors maximize the efficiency by maintaining the combustion on the optimal and stable level. Navien offers the optional built-in recirculation system with buffer tank, which significantly reduces "cold water sandwiches" as no minimum flow rate is required.


Hope this article helped you find the answer who makes the best tankless water heater and what is the best water heater to buy. The top models, as you can check, are coming from the industry leaders in tankless technology and are designed to offer the best quality, features and performance.

Related Articles

    (All pictures are courtesy of