Rheem SPEX90
Rheem SPEX90 is in the DOE listing as of Oct 26, 2026.
It has a certified UEF of 0.96 and a certified flow of 0.9 gal/min at a 67°F rise.
Its certified flow is 0.9 gal/min at a 67°F rise, while Rheem advertises 2.0 gal/min, no rise stated (Read Oct 5, 2026), so a comparison at the same rise is not possible.
- Electric tankless water heater
- 1 listed model
ENERGY STAR certification does not cover this type of water heater.
Certified and advertised figures
- Flow at a 67°F rise
- 0.9gallons per minuteCertified
- Advertised flow
- 2.0gallons per minuteRheem, no rise stated
- UEF
- 0.96Uniform energy factor
Your fixtures at once
Change your hour and flowFlow where you live
Colder incoming water needs a bigger rise, so the heater gives less flow.
- 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 0.9 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 |
|---|---|---|---|---|
| Flow | 2.0 gal/min, no rise stated | 0.9 gal/min at a 67°F rise | Rheem | Read Oct 5, 2026 |
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| RTEH90 | 0.96 | 0.9 | 93% | Very small |
UEF is the uniform energy factor. A dash means the model has no such figure.
It heats 0.9 gallons per minute of water by 67°F in the test. The electric tankless type has a median flow of 0.7 gallons per minute. Of 337 electric tankless models, 114 have a higher flow than this one.
In tests, 96% of the energy it uses ends up as hot water (UEF 0.96). Its test simulated a day of very small hot water use (its draw pattern). Of 272 electric tankless models with the same draw pattern, 77 have a higher UEF and 121 a lower one. For its type and draw pattern, its UEF sits at the median. When it runs, 93% of the energy it uses reaches the water (its recovery efficiency).
Its test figures match those of 2 other basic models. Those basic models are sold with EEMAX and KWICKSHOT as their brand names.
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.