A. O. Smith ACTH-199M-(N,P) 1
A. O. Smith ACTH-199M-(N,P) 1 is a gas tankless water heater from A. O. Smith rated 5.8 GPM at a 0.95 UEF.
| Uniform Energy Factor (UEF) | 0.95 |
|---|---|
| Annual gas use (natural gas) | 178 therms/yr |
| Recovery efficiency | 97 % |
| Annual propane use | 194.53 gal/yr |
| Fuel | Natural Gas, Propane |
|---|
| Max flow rate | 5.8 GPM |
|---|---|
| Draw pattern | High |
| Minimum activation flow | 1 GPM |
| Gas input rate | 199 kBTU/h |
|---|
| Max current draw | 5 A |
|---|---|
| Vent type | Power Direct Vent, Power Vent |
| Vent size | 3 / 2 |
| Smart / connected capable | No |
|---|
| Width | 17 in |
|---|---|
| Depth | 16 in |
| ENERGY STAR certified | Yes |
|---|
Real flow rate by climate
A tankless heater's usable flow depends on how far it must raise incoming water temperature. Sustained hot-water flow of the A. O. Smith ACTH-199M-(N,P) 1 at common temperature rises (a typical shower uses about 2 GPM of mixed water):
| Temperature rise | Climate | Sustained flow | Simultaneous showers |
|---|---|---|---|
| 45 °F | Warm climate (~75 °F groundwater) | 5.8 GPM | 2 |
| 55 °F | Mild climate (~65 °F groundwater) | 5.8 GPM | 2 |
| 70 °F | Cold climate (~50 °F groundwater) | 5.4 GPM | 2 |
| 77 °F | DOE test condition | 4.9 GPM | 2 |
Compare the A. O. Smith ACTH-199M-(N,P) 1
- A. O. Smith ACTH-199M-(N,P) 1 vs American ATHR-160M 1 (MTHR-160M 1)
- A. O. Smith ACTH-199M-(N,P) 1 vs American ATHR-160M 1 (MTHR-160X3 1)
- A. O. Smith ACTH-199M-(N,P) 1 vs American ATHR-180M 1 (MTHR-180M 1)
- A. O. Smith ACTH-199M-(N,P) 1 vs Bosch Greentherm (T9800 SE 160)
- A. O. Smith ACTH-199M-(N,P) 1 vs Bosch Greentherm (T9800 SEO 160)
- A. O. Smith ACTH-199M-(N,P) 1 vs Bosch Greentherm (T9900 SE 160)
- A. O. Smith ACTH-199M-(N,P) 1 vs Bradford White RTGR150N1
- A. O. Smith ACTH-199M-(N,P) 1 vs Bradford White RTGR150X1
Similar water heaters
- A. O. Smith T-H3-OS-N 1 (ACT-199O-N 1) (UEF 0.95)
- A. O. Smith T-H3-OS-N 1 (ACT-199O-P 1-1) (UEF 0.95)
- A. O. Smith T-H3-OS-N 1 (ATO-540H 1) (UEF 0.95)
- A. O. Smith T-H3-OS-N 1 (ATO-540H 1-1) (UEF 0.95)
- A. O. Smith T-H3-OS-N 1 (ATO-540HX3-N 1) (UEF 0.95)
- A. O. Smith T-H3-OS-N 1 (ATO-540HX3-P 1-1) (UEF 0.95)
Frequently asked questions
Is the A. O. Smith ACTH-199M-(N,P) 1 ENERGY STAR certified?
Yes, the A. O. Smith ACTH-199M-(N,P) 1 holds a current ENERGY STAR certification for water heating efficiency (UEF 0.95).
How much does the A. O. Smith ACTH-199M-(N,P) 1 cost to run per year?
About $258 per year at national average energy rates, based on its certified annual energy use under the DOE test draw pattern. Your rate and usage change this figure.
What venting does the A. O. Smith ACTH-199M-(N,P) 1 use?
The A. O. Smith ACTH-199M-(N,P) 1 uses Power Direct Vent, Power Vent venting with 3 / 2 in vent connections. Matching the existing vent type is usually the cheapest replacement path.
Is the A. O. Smith ACTH-199M-(N,P) 1 a smart water heater?
No, the A. O. Smith ACTH-199M-(N,P) 1 is not connected-capable — it has no app connectivity or demand-response support.
Sources
- data.energystar.gov (retrieved 2026-07-17)