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Westinghouse HW120

Westinghouse HW120 is in the DOE listing as of Oct 19, 2026.

  • Gas tankless water heater
  • 2 listed models

Not listed as ENERGY STAR certified on Oct 19, 2026.

Its figures are also listed under Fogatti FDG-CS120.

Flow at a 67°F rise
2.9–3.0gallons per minuteCertified
Advertised flow
5.1gallons per minuteThe Home Depot, up to, no rise stated
UEF
0.82–0.84Uniform energy factor

The 2 listed models differ. A range runs from the lowest figure to the highest.

See it among every gas tankless model

Flow 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 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.

Advertised and certified figures

Westinghouse HW120: advertised and certified
Westinghouse HW120: advertised and certified UEF: advertised 0.81, certified 0.82. Flow: advertised 5.1 gal/min, certified 2.9 gal/min (advertised up to, no rise stated, certified at a 67°F rise). Flow: advertised 5.1 gal/min, certified 2.9 gal/min (advertised at a 35°F rise, certified at a 67°F rise). Flow: advertised 4.7 gal/min, certified 2.9 gal/min (advertised at a 45°F rise, certified at a 67°F rise). UEF Advertised 0.81 Certified 0.82 Flow · advertised up to, no rise stated, certified at a 67°F rise Advertised 5.1 gal/min Certified 2.9 gal/min Flow · advertised at a 35°F rise, certified at a 67°F rise Advertised 5.1 gal/min Certified 2.9 gal/min Flow · advertised at a 45°F rise, certified at a 67°F rise Advertised 4.7 gal/min Certified 2.9 gal/min
FigureAdvertisedCertifiedAdvertiserRead
UEF 0.81 0.82 The Home Depot Archived copy, Sep 17, 2025
Flow up to 5.1 gal/min, no rise stated 2.9 gal/min at a 67°F rise The Home Depot Archived copy, Sep 17, 2025
Flow 5.1 gal/min at a 35°F rise 2.9 gal/min at a 67°F rise The Home Depot Archived copy, Sep 17, 2025
Flow 4.7 gal/min at a 45°F rise 2.9 gal/min at a 67°F rise The Home Depot Archived copy, Sep 17, 2025

See how advertised flow compares across tankless models

Certified figures by listed model

Model numberUEFFlow at a 67°F rise (gal/min)Recovery efficiencyDraw pattern
HW120A1G-LP0.843.083%Medium
HW120A1G-NG0.822.981%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 median gas tankless model heats 4.8 gallons per minute by 67°F. Of 487 gas tankless models, 467 have a higher flow than this one.

On Oct 19, 2026, this heater was not listed as ENERGY STAR certified. Its listed models turn 82 to 84% of the energy used into hot water (UEF 0.82 to 0.84). In the test, daily hot water use was set to medium (its draw pattern). Its UEF is lower than that of 21 of the 77 gas tankless models with its draw pattern. A UEF of 0.82 is the median for its type and draw pattern.

Its 2 model numbers are HW120A1G-LP and HW120A1G-NG. Its test figures match those of 3 other basic models. Those basic models are sold with Fogatti, Mizudo, and ORBEK as their brand names. You can find the whole group on the page for the Fogatti FDG-CS120.

It may qualify for one rebate program if it meets terms its figures do not show.

Also listed as

They carry every figure in the table above.

Rebates

ProgramStateStatusProgram 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.

Updated Oct 19, 2026 · Methodology

Not covered

  • Changes to an advertised figure after the date beside it.