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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.
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 and an endless supply of hot water. Other benefits include 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 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 than it is needed (oversized), operating costs will increase. At the same time, if you get a model that cannot meet the demand (undersized), especially at peak time, you won’t get enough hot water, resulting in colder showers and unpleasant experiences.
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 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 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?
- Tankless for homes with up to 2 bathrooms
- Tankless for homes with 2-3 bathrooms
- Tankless for homes with 3 bathrooms and up
- Comparing tankless/condensing
- Price comparison
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 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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