EEMAX ECO18
EEMAX ECO18 is in the DOE listing as of Oct 19, 2026.
- Electric tankless water heater
- 3 listed models
ENERGY STAR certification does not cover this type of water heater.
Its figures are also listed under Rheem ECO18.
Certified and advertised figures
- Flow at a 67°F rise
- 1.7gallons per minuteCertified
- Advertised flow
- 4.9gallons per minuteSupplyHouse, no rise stated
- UEF
- 0.94Uniform energy factor
Your fixtures at once
Change your hour and flowFlow where you live
A bigger rise from colder incoming water leaves the heater with 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 1.6 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 | 0.98 | 0.94 | The Home Depot | Archived copy, Sep 19, 2025 |
| Flow | 3.5 gal/min, no rise stated | 1.7 gal/min at a 67°F rise | Lowe's | Archived copy, Jun 18, 2026 |
| Flow | 4.9 gal/min, no rise stated | 1.7 gal/min at a 67°F rise | SupplyHouse | Archived copy, May 15, 2025 |
| Flow | up to 4.9 gal/min, no rise stated | 1.7 gal/min at a 67°F rise | SupplyHouse | Archived copy, May 15, 2025 |
| Flow | 3.6 gal/min, no rise stated | 1.7 gal/min at a 67°F rise | The Home Depot | Archived copy, Sep 19, 2025 |
| Flow | 3.1 gal/min at a 40°F rise | 1.7 gal/min at a 67°F rise | SupplyHouse | Archived copy, May 15, 2025 |
| Flow | 2.1 gal/min at a 50°F rise | 1.7 gal/min at a 67°F rise | SupplyHouse | Archived copy, May 15, 2025 |
| Flow | 2.0 gal/min at a 60°F rise | 1.7 gal/min at a 67°F rise | SupplyHouse | Archived copy, May 15, 2025 |
| Flow | 1.8 gal/min at a 70°F rise | 1.7 gal/min at a 67°F rise | SupplyHouse | Archived copy, May 15, 2025 |
| Flow | 3.6 gal/min at a 35°F rise | 1.7 gal/min at a 67°F rise | The Home Depot | Archived copy, Sep 19, 2025 |
| Flow | 2.9 gal/min at a 45°F rise | 1.7 gal/min at a 67°F rise | The Home Depot | Archived copy, Sep 19, 2025 |
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| EEM24018 | 0.94 | 1.7 | 98% | — |
| HA018240 | 0.94 | 1.7 | 98% | — |
| PR018240 | 0.94 | 1.7 | 98% | — |
UEF is the uniform energy factor. A dash means the model has no such figure.
At a 67°F rise, its flow in the test is 1.7 gallons per minute. The median electric tankless model heats 0.7 gallons per minute by 67°F. Of 337 electric tankless models, 40 have a higher flow than this one.
In tests, 94% of the energy went to hot water, so its UEF is 0.94. Of the energy it spends heating water, 98% ends up in it (its recovery efficiency).
It is sold as EEM24018, HA018240, and PR018240. There are 2 more basic models with the same test figures. The ECOSMART and Rheem brands list one or more of them. You can find the whole group on the page for the Rheem ECO18.
Also listed as
They carry every figure in the table above.
- Every EEMAX basic model
- Every electric tankless water heater certified at 1.0 to 1.9 gallons per minute
- Every electric tankless water heater
Not covered
- Changes to an advertised figure after the date beside it.