Tankless water heaters comparison is about comparing popular gas-powered and on-demand models from North America, and it includes manufacturers such as Rinnai, Takagi, Navien, Noritz, Rheem, Bosch, AO Smith, and Bradford White.
The article will cover the most important info you need when selecting and price comparison, presented in easy-to-understand charts. All 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 find. Reviewed models are powered by the natural gas and are designed for indoor installation, include the direct ignition and the 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.
Brand Model |
Gas Input (Btu) Min / Max |
Energy Factor EF |
Capacity (gal.) |
Approx. size (Inch) |
Weight (Lb) |
Remote or Digital Control |
Link cable |
AO Smith ATI-110 |
19,500 140,000 |
0.82 | 0.4-6.6 | 7x14x21 | 38 | Yes | No |
Bradford White TG-150I |
15,000 150,000 |
0.82 | 0.6-5 | 9x14x23 | 50 | Yes | No |
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 Energy Star approved, which is one of the main factors when buying.
Brand Model |
Gas Input (Btu) Min / Max |
Energy Factor EF |
Capacity (gal.) |
Approx. size (Inch) |
Weight (Lb) |
Remote or Digital Control |
Link cable |
AO Smith ATI-310 |
11,000 190,000 |
0.82 | 0.4-8 | 9x14x21 | 43 | No | No |
Bradford White TG-180I |
15,000 180,000 |
0.82 | 0.6-7.5 | 9x14x23 | 50 | No | No |
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 |
Brand Model |
Gas Input (Btu) Min / Max |
Energy Factor EF |
Capacity (gal.) |
Approx. size (Inch) |
Weight (Lb) |
Remote or Digital Control |
Link cable |
AO Smith ATI-510 |
11,000 199,000 |
0.82 | 0.4-10 | 9x14x21 | 45 | Yes | Yes |
Bradford White TG-199I |
15,000 199,000 |
0.82 | 0.6-9.4 | 9x14x23 | 50 | Yes | No |
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 |
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 |
AO Smith ATI-520H |
13,000 199,000 |
0.91 | 0.4-9 | 12x19x26 | 73 | Yes | Yes |
Bradford White TGHE-160I TGHE-199I |
9,500 157,000 |
0.96 | 0.26-8 | 10x19x26 | 64 | Yes | ? |
9,500 199,000 |
0.94 | 0.26-9.8 | 10x19x26 | 71 | Yes | ? | |
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 | |
Navien NR180 NR210 NR240 |
15,000 150,000 |
0.94 | 0.5-8 | 14x17x28 | 67 | Yes | Yes |
17,000 180,000 |
0.94 | 0.5-9.6 | 15x17x28 | 77 | Yes | Yes | |
20,000 199,000 |
0.95 | 0.5-10.6 | 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 |
Brand / Model (indoor) | Price ($) Approximate |
AO Smith 8 GPM (non-condensing) 9 GPM (condensing) |
886 1463 |
Bosch 8.3 GPM (non-condensing) 9.2 GPM (condensing) |
990 1269 |
Noritz 7.5 GPM (non-condensing) 9.3 GPM (condensing) |
1124 1818 |
Navien 9.6 GPM (condensing) |
1362 |
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 |
See the reviews and prices on Amazon.com.
The above tankless water heater comparison chart contains the information you might need when selecting the right model. If you require more details about 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.
Do you have a great story about this or question to ask? Share it - Ask It - Help!