Tankless Water Heater
Comparison Table

Tankless water heaters comparison is about comparing popular gas-powered and on-demand models from North America, and it compares manufacturers such as Rinnai, Takagi, Noritz, Rheem, and Bosch.

The article will cover essential features and tips you need when selecting and sizing, including the price comparison, all presented in easy-to-understand charts. All tankless water heaters shown here are for residential potable water heating, with and without a condensing technology.

Rinnai tankless water heater

There will be several comparison charts for your convenience and easy selection. Reviewed models are powered by natural gas and are designed for indoor installation; they include a direct ignition system and modulating gas burner. The tankless water heater comparison article will not cover outdoor models that are using propane gas as they have similar features/technical data.

Why tankless

When you compare tankless vs. tank-type, you will see that tankless has many advantages, such as on-demand heating, an endless supply of hot water, accurate control, efficient and low-cost operation, fast delivery with recirculation, small size, extended warranty, durability, and reliable service.

According to some studies, water heaters consume on average 1/5 of an entire home’s energy use. That is why it is essential to make the right choice. But as there are many brands and options, selecting the best model might become challenging. So, let’s compare tankless water heaters so you can buy the best model.

Tip: Don’t buy the cheapest one, because tankless are built to last, so the most efficient one will save you the most.

This article is for homeowners who need a water heater for their 2+-bath homes. They should look for the whole-house tankless water heaters, which have at least 140,000 BTU of power.

What size do I need?

If the tankless water heater is correctly sized, the water heater will provide a sufficient amount of hot water efficiently and for a long time. And the best of all, it will increase the comfort and help you save.

If you choose a heater that gives you more power and water flow that it is needed (oversized), operating costs will increase, while if you get a model which cannot meet the demand (undersized), especially at the peak time, you won’t get enough hot water, and that will result in colder showers and unpleasant experience.

It is recommended to select a tankless water heater based on the amount of hot water that is needed at peak times, which often occurs before the work or school and in the evenings. Simply add up the flow rates of all the fixtures that you plan to open at one time.

What is essential when selecting the right size of the tankless water heater are the water flow (in GPM), incoming and outgoing water temperatures.

For the reference, use the following data when sizing the tankless:

Shower – 2 GPM

Handwashing sink – 0.5 GPM

Kitchen sink – 1-2 GPM

Dishwasher – 1-2 GPM

Washing machine – 1-1.5 GPM

Bathtub – over 4 GPM

What do we compare?

Comparing tankless water heaters designed for smaller homes (1-2 bathrooms)

Brand
Model
Gas Input
(Btu)
Min / Max
Energy
Factor
EF
Capacity
(gal.)
Approx.
size
(Inch)
Weight
(Lb)
Remote
or
Digital
Control
Link
cable
Bosch
520 PN
520 HN
660 EF
30,735-117,000 0.76 0.5 - 5.2 9X18X26 35 No No
30,735-117,000 0.78 0.6 - 5.2 9X18X26 35 No No
20,000-140,000 0.82 0.5 - 6.6 7X14X21 36 No No
Noritz
NR66
20,000-140,000 0.82 0.5-6.6 7X14X21 36 No No
Rheem
RTG-64
11,000-150,000 0.82 0.4-6.4 9x14x26 54 Yes Yes
Rinnai
RV53
V65
15,000-150,000 0.82 0.6-5.3 9x14x24 51 No No
10,300-150,000 0.82 0.4-6.6 9x14x23 46 Yes No
Takagi
T-KJr2
19,500-140,000 0.82 0.4-6.6 7x14x20 33 Yes No

Tankless water heaters with the energy factor (EF) of 0.82 or higher are high efficient but not Energy Star approved.

Tankless water heaters for 2-3 bath-homes compared

Brand
Model
Gas Input
(Btu)
Min / Max
Energy
Factor
EF
Capacity
(gal.)
Approx.
size
(Inch)
Weight
(Lb)
Remote
or
Digital
Control
Link
cable
Bosch
830 ES
19,900-175,000 0.83 0.5-8.3 11x18x31 67 Yes Yes
Noritz
NR71
NR83
25,000-180,000 0.83 0.5-7.1 7X14X24 41 No No
18,000-180,000 0.82 0.5-8.3 9X14X21 49 Yes Yes
Rheem
RTG-84
11,000-180,000 0.82 0.4-8.4 10x14x26 54 Yes Yes
Rinnai
V75
RL75
10,300-180,000 0.82 0.4-7.5 9x14x23 46 Yes No
10,300-180,000 0.82 0.4-7.5 9x14x23 46 Yes No
Takagi
T-K3
T-K4
11,000-199,000 0.84 0.5-7 9x14x21 40 Yes No
11,000-190,000 0.82 0.4-8 9x14x21 38 Yes No

Comparison table for tankless water heaters designed for more than 3 bath-homes

Brand
Model
Gas Input
(Btu)
Min / Max
Energy
Factor
EF
Capacity
(gal.)
Approx.
size
(Inch)
Weight
(Lb)
Remote
or
Digital
Control
Link
cable
Bosch
940 ES
19,900-199,900 0.83 0.5-9.4 11x18x31 67 Yes Yes
Noritz
NR981
NR111
16,000-199,900 0.82 0.5-9.8 9x14x24 54 Yes Yes
11,000-250,000 N/A 0.5-11.1 9x18x24 62 Yes Yes
Rheem
RTG-95
11,000-199,900 0.82 0.4-9.5 10x14x26 54 Yes Yes
Rinnai
RL94
10,300-199,000 0.82 0.4-9.8 9x14x23 46 Yes No
Takagi
T-D2
11,000-190,000 0.83 0.4-10 9x14x20 39 Yes Yes

Condensing tankless models compared

When comparing condensing and non-condensing tankless water heaters, you will see that the main difference is that condensing models utilize the second, stainless steel heat exchanger, which uses the flue heat for the ultra-efficient water heating. 

Brand/
Model 
Gas Input
(Btu)
Min / Max
Energy
Factor
EF
Capac
(gal.)
Approx.
size
(Inch)
Weight
(Lb)
Remote
or
Digital
Control
Link
cable
Bosch
C 950 ES
C 1050 ES
C1210 ES
19,900-199,000 0.92 0.5-9.2 11x18x31 74 Yes Yes
19,900-175,000 0.94 0.5-10.5 11x18x31 74 Yes Yes
25,000-225,000 N/A 0.5-12.1 11x18x31 88 Yes Yes
17,000-180,000 0.94 0.5-9.6 15x17x28 77 Yes Yes
Noritz
NRC83
NRC98
NRC111
16,000-157,000 0.92 0.5-8.3 9x18x24 58 Yes Yes
16,000-180,000 0.92 0.5-9.8 9x18x24 58 Yes Yes
11,000-199,900 0.92 0.5-11.1 9x18x24 66 Yes Yes
Rheem
RTGH 84
RTGH 95
11,000-157,000 0.94 0.4-8.4 10x19x28 ~60 Yes Yes
11,000-199,900 0.84 0.4-9.5 10x19x28 ~60 Yes Yes
Rinnai
RU80
RU98
15,200-152,000 0.96 0.4-8 10x18x26 71 Yes No
15,200-199,000 0.95 0.4-9.8 10x18x26 62 Yes No
Takagi
T-H2
T-H2S
T-H3J
13,000-199,000 0.91 0.4-9 12x19x26 73 Yes No
13,000-180,000 0.91 0.4-8 12x19x26 73 Yes No
15,000-160,000 0.95 0.4-6.6 11x18x23 58 Yes No

Price comparison

Brand / Model (indoor) Price ($)
Approximate
Bosch
8.3 GPM (non-condensing)
9.2 GPM (condensing)
990
1269
Noritz
7.5 GPM (non-condensing)
9.3 GPM (condensing)
1124
1818
Rheem
8.4 GPM (non-condensing)
9.5 GPM (condensing)
857
1313
Rinnai
7.5 GPM (non-condensing)
9.8 GPM (condensing)
1000
1621
Takagi
8 GPM (non-condensing)
9 GPM (condensing)
852
1395

The above tankless water heater comparison chart contains the information you might need when selecting the right model. If you require more details about a specific brand or model, we recommended our reviews found in the links provided on the main navigation bar on the left or below, in the popular articles section.

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