ORBEK HS120
ORBEK HS120 is in the DOE listing as of Oct 19, 2026.
- Gas tankless water heater
- 4 listed models
Not listed as ENERGY STAR certified on Oct 19, 2026.
Its figures are also listed under Fogatti FDG-CS120.
Certified figures
- Flow at a 67°F rise
- 2.9–3.0gallons per minute
- UEF
- 0.82–0.84Uniform energy factor
The 4 listed models differ. A range runs from the lowest figure to the highest.
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 2.8 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 |
|---|---|---|---|---|
| HS120A0W-LP | 0.84 | 3.0 | 83% | Medium |
| HS120A0W-NG | 0.82 | 2.9 | 81% | Medium |
| HS120A1W-LP | 0.84 | 3.0 | 83% | Medium |
| HS120A1W-NG | 0.82 | 2.9 | 81% | Medium |
UEF is the uniform energy factor. A dash means the model has no such figure.
Its flow at a 67°F rise is 2.9 to 3.0 gallons per minute, by model number. The gas tankless type has a median flow of 4.8 gallons per minute. Among 487 gas tankless models, 467 give more flow at a 67°F rise.
It was not listed as ENERGY STAR certified on Oct 19, 2026. Its listed models turn 82 to 84% of the energy used into hot water (UEF 0.82 to 0.84). The daily hot water use in the test, called its draw pattern, was medium. Of 77 gas tankless models with the same draw pattern, 21 have a higher UEF and 51 a lower one. On its draw pattern, the median gas tankless UEF is 0.82.
The test figures are not all the same for its 4 model numbers. There are 3 more basic models with the same test figures. Those basic models are sold with Fogatti, Mizudo, and Westinghouse as their brand names. For the full group, see the Fogatti FDG-CS120.
It may qualify for one rebate program 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 if it meets the other terms | Its own page |
Programs change their terms. Check the program's own page before you buy.
- Every ORBEK basic model
- Every gas tankless water heater certified below 4.0 gallons per minute
- Every gas tankless water heater
- The most-searched gas tankless models side by side
Not covered
- Advertised figures. We have none on file for this model.