State TK-110U-E 2**
State TK-110U-E 2** is in the DOE listing as of Oct 19, 2026.
- Gas tankless water heater
- 1 listed model
Not listed as ENERGY STAR certified on Oct 19, 2026.
Its figures are also listed under A. O. Smith TK-110U-E 2**.
Certified and advertised figures
- Flow at a 67°F rise
- 3.5gallons per minuteCertified
- Advertised flow
- 3.5gallons per minuteState, up to, no rise stated
- UEF
- 0.81Uniform 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 3.4 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 | 0.81 | 0.81 | State | Read Oct 4, 2026 |
| UEF | up to 0.81 | 0.81 | State | Read Oct 4, 2026 |
| Flow | 3.5 gal/min at a 67°F rise | 3.5 gal/min at a 67°F rise | State | Read Oct 4, 2026 |
| Flow | up to 3.5 gal/min, no rise stated | 3.5 gal/min at a 67°F rise | State | Read Oct 4, 2026 |
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| GTS-110U-E 2** | 0.81 | 3.5 | 83% | Medium |
UEF is the uniform energy factor. A dash means the model has no such figure.
It heats 3.5 gallons per minute of water by 67°F in the test. The gas tankless type has a median flow of 4.8 gallons per minute. Of 487 gas tankless models, 426 have a higher flow than this one.
It was not listed as ENERGY STAR certified on Oct 19, 2026. In tests, 81% of the energy it uses ends up as hot water (UEF 0.81). Its test simulated a day of medium hot water use (its draw pattern). Its UEF is lower than that of 48 of the 77 gas tankless models with its draw pattern. A UEF of 0.82 is the median for its type and draw pattern. While it heats water, 83% of the energy used goes into the water (its recovery efficiency).
There are 6 more basic models with the same test figures. Each of them is listed under a different brand. For the full group, see the A. O. Smith TK-110U-E 2** page.
Also listed as
They carry every figure in the table above.
- Every State 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
- Changes to an advertised figure after the date beside it.