GSW WATER HEATERS GTM-140X3-N 1**
GSW WATER HEATERS GTM-140X3-N 1** is in the ENERGY STAR list as of Oct 19, 2026.
- Gas tankless water heater
- 1 listed model
No certified figures were found under this model number. Units made for another brand are often certified under that brand's basic model.
Its figures are also listed under A. O. Smith ATM-140M-N 1**.
Certified figures
- Flow at a 67°F rise
- 4.1gallons per minute
- UEF
- 0.95Uniform energy factor
Your fixtures at once
Change your hour and flowFlow where you live
The heater gives less flow when colder incoming water needs a bigger rise.
- 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 3.9 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.
Product history
GSW WATER HEATERS GTM-140X3-N 1** has a recorded ENERGY STAR market-availability date of Aug 28, 2026. It first appeared in the ENERGY STAR list between February 2026 and October 2026.
ENERGY STAR certified models
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency |
|---|---|---|---|
| GTM-140X3-N 1** | 0.95 | 4.1 | 97% |
At a 67°F rise, its flow in the test is 4.1 gallons per minute. The median gas tankless model heats 4.8 gallons per minute by 67°F. Of 487 gas tankless models, 368 have a higher flow than this one.
Its single model number, GTM-140X3-N 1**, is ENERGY STAR certified. In the test, 5% of its energy does not reach the hot water (UEF 0.95). The daily hot water use in the test, called its draw pattern, was high. Of 399 gas tankless models with the same draw pattern, 49 have a higher UEF and 217 a lower one. A UEF of 0.93 is the median for its type and draw pattern. When it runs, 97% of the energy it uses reaches the water (its recovery efficiency).
Its test figures match those of 8 other basic models. In all, 7 other brands list one or more of them. For the full group, see the A. O. Smith ATM-140M-N 1** page.
In 7 states, 6 rebate programs may accept it. Another 2 rebate programs may accept it 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 | Its own page |
| Colorado Springs Utilities Water heater rebate (gas storage, gas tankless) | CO | May qualify | Its own page |
| Nicor Gas Energy Efficiency Rebates for Your Home (gas tankless) | IL | May qualify if it meets the other terms | Its own page |
| DTE Energy Water Heaters (gas storage, gas tankless) | MI | May qualify | Its own page |
| Xcel Energy MINNESOTA RESIDENTIAL ENERGY EFFICIENCY PROGRAMS (gas storage, gas tankless) | MN | May qualify | Its own page |
| PSE&G Tankless Water Heaters | NJ | May qualify | Its own page |
| Energy Trust of Oregon Residential Incentives | OR, WA | May qualify | Its own page |
| Focus on Energy (gas tankless) | WI | 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 GSW WATER HEATERS basic model
- Every gas tankless water heater certified at 4.0 to 4.9 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.