A. O. Smith ACTH-199M-(N,P) 1**
A. O. Smith ACTH-199M-(N,P) 1** is in the DOE listing as of Oct 26, 2026 and is in the ENERGY STAR list as of Oct 26, 2026.
It has a certified UEF of 0.95 and a certified flow of 5.8 gal/min at a 67°F rise.
- Gas tankless water heater
- 1 listed model
Certified figures
- Flow at a 67°F rise
- 5.8gallons per minute
- UEF
- 0.95Uniform energy factor
Your fixtures at once
Change your hour and flowFlow where you live
A bigger rise from colder incoming water leaves the heater with 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 5.6 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
A. O. Smith ACTH-199M-(N,P) 1** was in the DOE listing by Oct 1, 2026.
A. O. Smith ACTH-199M-(N,P) 1** has a recorded ENERGY STAR market-availability date of Jun 16, 2026. It first appeared in the ENERGY STAR list between February 2026 and August 2026.
Certified figures by listed model
| Model number | UEF | Flow at a 67°F rise (gal/min) | Recovery efficiency | Draw pattern |
|---|---|---|---|---|
| ACTH-199M-(N,P) 1** | 0.95 | 5.8 | 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) | Recovery efficiency |
|---|---|---|---|
| ACTH-199M-(N,P) 1** | 0.95 | 5.8 | 97% |
It warms 5.8 gallons per minute of water from 58°F to 125°F in the test. The gas tankless type has a median flow of 4.8 gallons per minute. Of 487 gas tankless models, 26 have a higher flow than this one.
It is ENERGY STAR certified under its single model number. In tests, 95% of the energy it uses ends up as hot water (UEF 0.95). In the test, daily hot water use was set to high (its draw pattern). Of 399 gas tankless models with the same draw pattern, 49 have a higher UEF. A UEF of 0.93 is the median for its type and draw pattern. While it heats water, 97% of the energy used goes into the water (its recovery efficiency).
There are 3 more basic models with the same test figures. Those basic models are sold with American, Lochinvar, and State as their brand names.
In 7 states, 6 rebate programs may accept it. 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 A. O. Smith 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.