Rheem ECO POU 3.5
Rheem ECO POU 3.5 is in the DOE listing as of Oct 26, 2026.
It has a certified UEF of 0.95 and a certified flow of 0.3 gal/min at a 67°F rise.
Its certified flow is 0.3 gal/min at a 67°F rise, while Rheem advertises 0.9 gal/min, no rise stated (Read Oct 4, 2026), so a comparison at the same rise is not possible.
- Electric tankless water heater
- 6 listed models
ENERGY STAR certification does not cover this type of water heater.
Certified and advertised figures
- Flow at a 67°F rise
- 0.3gallons per minuteCertified
- Advertised flow
- 0.9gallons per minuteRheem, no rise stated
- UEF
- 0.95Uniform 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 0.3 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 | 0.95 | 0.95 | The Home Depot | Archived copy, May 20, 2025 |
| Flow | 0.9 gal/min, no rise stated | 0.3 gal/min at a 67°F rise | Rheem | Read Oct 4, 2026 |
| Flow | 1.5 gal/min, no rise stated | 0.3 gal/min at a 67°F rise | SupplyHouse | Archived copy, Jun 5, 2023 |
| Flow | 0.9 gal/min, no rise stated | 0.3 gal/min at a 67°F rise | SupplyHouse | Archived copy, Jun 5, 2023 |
| Flow | 0.68 gal/min at a 35°F rise | 0.3 gal/min at a 67°F rise | The Home Depot | Archived copy, May 20, 2025 |
| Flow | 0.53 gal/min at a 45°F rise | 0.3 gal/min at a 67°F rise | The Home Depot | Archived copy, May 20, 2025 |
| Flow | 0.43 gal/min at a 55°F rise | 0.3 gal/min at a 67°F rise | The Home Depot | Archived copy, May 20, 2025 |
| Flow | 0.37 gal/min at a 65°F rise | 0.3 gal/min at a 67°F rise | The Home Depot | Archived copy, May 20, 2025 |
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| RETEX-04 | 0.95 | 0.3 | 98% | Very small |
| RETEX-04T | 0.95 | 0.3 | 98% | Very small |
| RMTEX-04 | 0.95 | 0.3 | 98% | Very small |
| RMTEX-04T | 0.95 | 0.3 | 98% | Very small |
| RTEX-04 | 0.95 | 0.3 | 98% | Very small |
| RTEX-04T | 0.95 | 0.3 | 98% | Very small |
UEF is the uniform energy factor. A dash means the model has no such figure.
It heats 0.3 gallons per minute of water by 67°F in the test. The median flow among electric tankless models is 0.7 gallons per minute. Of 337 electric tankless models, 271 have a higher flow than this one.
In the test, 5% of its energy does not reach the hot water (UEF 0.95). In the test, daily hot water use was set to very small (its draw pattern). Its UEF is lower than that of 151 of the 272 electric tankless models with its draw pattern. For its type and draw pattern, the median UEF is 0.96. Of the energy it spends heating water, 98% ends up in it (its recovery efficiency).
It is sold under 6 model numbers in all. Its test figures match those of 3 other basic models. Of those, one or more are under the ECOSMART, EEMAX, and Shenzhen Cansirong Trading Co., Ltd brands.
Also listed as
They carry every figure in the table above.
- Every Rheem basic model
- Every electric tankless water heater certified below 1.0 gallon per minute
- Every electric tankless water heater
Not covered
- Changes to an advertised figure after the date beside it.