Aquapower Mini-E 4-2
Aquapower Mini-E 4-2 is in the DOE listing as of Oct 19, 2026.
- Electric tankless water heater
- 1 listed model
ENERGY STAR certification does not cover this type of water heater.
Its figures are also listed under Stiebel Eltron Mini-E 4-2.
Certified figures
- Flow at a 67°F rise
- 0.4gallons per minute
- UEF
- 0.98Uniform 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 0.4 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.
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| AQM-E 4-2 | 0.98 | 0.4 | 98% | Very small |
UEF is the uniform energy factor. A dash means the model has no such figure.
It warms 0.4 gallons per minute of water from 58°F to 125°F in the test. The electric tankless type has a median flow of 0.7 gallons per minute. Among 337 electric tankless models, 233 give more flow at a 67°F rise.
In tests, 98% of the energy went to hot water, so its UEF is 0.98. In the test, daily hot water use was set to very small (its draw pattern). Among 272 electric tankless models on its draw pattern, 10 have a higher UEF. On its draw pattern, the median electric tankless UEF is 0.96. While it heats water, 98% of the energy used goes into the water (its recovery efficiency).
Its test figures match those of one other basic model. The brand name on that one is Stiebel Eltron. For the full group, see the Stiebel Eltron Mini-E 4-2 page.
Also listed as
They carry every figure in the table above.
- Every Aquapower basic model
- Every electric tankless water heater certified below 1.0 gallon per minute
- Every electric tankless water heater
Not covered
- Advertised figures. We have none on file for this model.