GSW WATER HEATERS T-H3S-DV-N 1**
GSW WATER HEATERS T-H3S-DV-N 1** is in the DOE listing as of Oct 19, 2026. GSW WATER HEATERS T-H3S-DV-N 1** is in the ENERGY STAR list as of Oct 19, 2026.
- Gas tankless water heater
- 2 listed models
Its figures are also listed under A. O. Smith T-H3S-DV-N 1**.
Certified figures
- Flow at a 67°F rise
- 5.4gallons per minute
- UEF
- 0.95Uniform 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 5.2 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 |
|---|---|---|---|---|
| GSWT-340H-N 1** | 0.95 | 5.4 | 97% | High |
| GSWT-340H-P 1*1 | 0.95 | 5.4 | 97% | High |
UEF is the uniform energy factor. A dash means the model has no such figure.
ENERGY STAR certified models
| Model number | UEF | Flow at a 67°F rise (gal/min) |
|---|---|---|
| GSWT-340H-N 1** | 0.95 | 5.4 |
| GSWT-340H-P 1*1 | 0.95 | 5.4 |
It heats 5.4 gallons per minute of water by 67°F in the test. The median gas tankless model heats 4.8 gallons per minute by 67°F. Of 487 gas tankless models, 100 have a higher flow than this one.
It has 2 model numbers that are ENERGY STAR certified. In tests, 95% of the energy it uses ends up as hot water (UEF 0.95). Its test simulated a day of high hot water use (its draw pattern). Its UEF is lower than that of 49 of the 399 gas tankless models with its draw pattern. 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).
It is sold as GSWT-340H-N 1** and GSWT-340H-P 1*1. There are 7 more basic models with the same test figures. Each of the 7 other brands lists one of them. For the full group, see the A. O. Smith T-H3S-DV-N 1**.
It may qualify for 6 rebate programs in 7 states. Another 2 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 5.0 to 5.9 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.