Takagi T-H3M-OS-N 1**
Takagi T-H3M-OS-N 1** 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 A. O. Smith T-H3M-OS-N 1**.
Certified figures
- Flow at a 67°F rise
- 3.5gallons per minute
- UEF
- 0.91Uniform 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 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.
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| T-H3M-OS-N 1** | 0.91 | 3.5 | 96% | Medium |
| T-H3M-OS-P 1*1 | 0.91 | 3.5 | 96% | Medium |
UEF is the uniform energy factor. A dash means the model has no such figure.
At a 67°F rise, its flow in the test is 3.5 gallons per minute. The median gas tankless model heats 4.8 gallons per minute by 67°F. Of 487 gas tankless models, 426 have a higher flow than this one.
On Oct 19, 2026, this heater was not listed as ENERGY STAR certified. In tests, 91% of the energy went to hot water, so its UEF is 0.91. Its test simulated a day of medium hot water use (its draw pattern). Its UEF is lower than that of 2 of the 77 gas tankless models with its draw pattern. For its type and draw pattern, the UEF runs from 0.81 to 0.97. While it heats water, 96% of the energy used goes into the water (its recovery efficiency).
Its 2 model numbers are T-H3M-OS-N 1** and T-H3M-OS-P 1*1. All of its test figures are shared by 5 other basic models. Each of them is listed under a different brand. For the full group, see the A. O. Smith T-H3M-OS-N 1**.
It may qualify for 2 rebate programs. 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 if it meets the other terms | 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 |
| 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 Takagi 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.