Rheem RTGH-S84I
Rheem RTGH-S84I is in the DOE listing as of Oct 26, 2026 and is in the ENERGY STAR list as of Oct 26, 2026.
It has a certified UEF of 0.96 and a certified flow of 4.6 gal/min at a 67°F rise.
Its certified flow is 4.6 gal/min at a 67°F rise, while Rheem advertises 8.4 gal/min, no rise stated (Read Oct 4, 2026), so a comparison at the same rise is not possible.
- Gas tankless water heater
- 18 listed models
Certified and advertised figures
- Flow at a 67°F rise
- 4.6gallons per minuteCertified
- Advertised flow
- 8.4gallons per minuteRheem, no rise stated
- UEF
- 0.96Uniform energy factor
Your fixtures at once
Change your hour and flowFlow where you live
The heater gives less flow when colder incoming water needs a bigger rise.
- Cold water
- Cold water must be at least 10°F colder than the hot water setting.
- Flow estimate
- The estimate uses the lowest certified flow among the listed models. It is about 4.4 gal/min at a 70°F rise.
Flow limits
- The estimate excludes the flow needed to turn the heater on, heat lost in pipes, and installation.
- Cold water from a well or long pipe run can differ from the temperature you enter.
- Without a stated flow limit, estimates for warmer water may exceed the heater’s actual flow.
Advertised and certified figures
| Figure | Advertised | Certified | Advertiser | Read |
|---|---|---|---|---|
| UEF | 0.96 | 0.96 | Rheem | Read Oct 4, 2026 |
| UEF | 0.96 | 0.96 | The Home Depot | Archived copy, Apr 28, 2025 |
| Flow | 8.4 gal/min, no rise stated | 4.6 gal/min at a 67°F rise | Rheem | Read Oct 4, 2026 |
| Flow | 8.4 gal/min at a 35°F rise | 4.6 gal/min at a 67°F rise | The Home Depot | Archived copy, Apr 28, 2025 |
| Flow | 6.9 gal/min at a 45°F rise | 4.6 gal/min at a 67°F rise | The Home Depot | Archived copy, Apr 28, 2025 |
| Flow | 5.6 gal/min at a 55°F rise | 4.6 gal/min at a 67°F rise | The Home Depot | Archived copy, Apr 28, 2025 |
| Flow | 4.8 gal/min at a 65°F rise | 4.6 gal/min at a 67°F rise | The Home Depot | Archived copy, Apr 28, 2025 |
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| CECOHS160IN | 0.96 | 4.6 | 97% | High |
| CECOHS160IP | 0.96 | 4.6 | 97% | High |
| CECOHSR160IN | 0.96 | 4.6 | 97% | High |
| CECOHSR160IP | 0.96 | 4.6 | 97% | High |
| CRTGH-S84I | 0.96 | 4.6 | 97% | High |
| CRTGH-SR84I | 0.96 | 4.6 | 97% | High |
| ECERTGH-S84I | 0.96 | 4.6 | 97% | High |
| ECERTGH-SR84I | 0.96 | 4.6 | 97% | High |
| ECOHS160IN | 0.96 | 4.6 | 97% | High |
| ECOHS160IP | 0.96 | 4.6 | 97% | High |
| ECOHSR160IN | 0.96 | 4.6 | 97% | High |
| ECOHSR160IP | 0.96 | 4.6 | 97% | High |
| RECTGH-S84IN | 0.96 | 4.6 | 97% | High |
| RECTGH-S84IP | 0.96 | 4.6 | 97% | High |
| RECTGH-SR84IN | 0.96 | 4.6 | 97% | High |
| RECTGH-SR84IP | 0.96 | 4.6 | 97% | High |
| RTGH-S84I | 0.96 | 4.6 | 97% | High |
| RTGH-SR84I | 0.96 | 4.6 | 97% | High |
UEF is the uniform energy factor. A dash means the model has no such figure.
ENERGY STAR certified models
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency |
|---|---|---|---|
| CECOHS160IN | 0.96 | 4.6 | 97% |
| CECOHS160IP | 0.96 | 4.6 | 97% |
| CECOHSR160IN | 0.96 | 4.6 | 97% |
| CECOHSR160IP | 0.96 | 4.6 | 97% |
| CRTGH-S84I | 0.96 | 4.6 | 97% |
| CRTGH-SR84I | 0.96 | 4.6 | 97% |
| ECERTGH-S84I | 0.96 | 4.6 | 97% |
| ECERTGH-SR84I | 0.96 | 4.6 | 97% |
| ECOHS160IN | 0.96 | 4.6 | 97% |
| ECOHS160IP | 0.96 | 4.6 | 97% |
| ECOHSR160IN | 0.96 | 4.6 | 97% |
| ECOHSR160IP | 0.96 | 4.6 | 97% |
| RECTGH-S84IN | 0.96 | 4.6 | 97% |
| RECTGH-S84IP | 0.96 | 4.6 | 97% |
| RECTGH-SR84IN | 0.96 | 4.6 | 97% |
| RECTGH-SR84IP | 0.96 | 4.6 | 97% |
| RTGH-S84I | 0.96 | 4.6 | 97% |
| RTGH-SR84I | 0.96 | 4.6 | 97% |
It heats 4.6 gallons per minute of water by 67°F in the test. The gas tankless type has a median flow of 4.8 gallons per minute. Among 487 gas tankless models, 300 give more flow at a 67°F rise.
It has 18 model numbers that are ENERGY STAR certified. In tests, 96% of the energy it uses ends up as hot water (UEF 0.96). In the test, daily hot water use was set to high (its draw pattern). Of 399 gas tankless models with the same draw pattern, 15 have a higher UEF and 350 a lower one. For its type and draw pattern, the median UEF is 0.93. While it heats water, 97% of the energy used goes into the water (its recovery efficiency).
A tag or quote may show any of its 18 model numbers. All of its test figures are shared by 3 other basic models. Of those, one or more are under the Friedrich, Richmond, and Ruud brands.
It may qualify for 6 rebate programs. Another 2 programs may accept it if it meets their other terms.
Also listed as
They carry every figure in the table above.
Rebates
| Program | State | Status | Program page |
|---|---|---|---|
| SoCalGas High-Efficiency or ENERGY STAR Certified Natural Gas Tankless Water Heaters rebate | CA | May qualify | Its own page |
| Colorado Springs Utilities Water heater rebate (gas storage, gas tankless) | CO | May qualify | Its own page |
| Nicor Gas Energy Efficiency Rebates for Your Home (gas tankless) | IL | May qualify if it meets the other terms | Its own page |
| DTE Energy Water Heaters (gas storage, gas tankless) | MI | May qualify | Its own page |
| Xcel Energy MINNESOTA RESIDENTIAL ENERGY EFFICIENCY PROGRAMS (gas storage, gas tankless) | MN | May qualify | Its own page |
| PSE&G Tankless Water Heaters | NJ | May qualify | Its own page |
| Energy Trust of Oregon Residential Incentives | OR, WA | May qualify | Its own page |
| Focus on Energy (gas tankless) | WI | May qualify if it meets the other terms | Its own page |
Programs change their terms. Check the program's own page before you buy.
- Every Rheem basic model
- Every gas tankless water heater certified at 4.0 to 4.9 gallons per minute
- Every gas tankless water heater
- The most-searched gas tankless models side by side
Not covered
- Changes to an advertised figure after the date beside it.