State ATHR-180M 1 (STHR-180X3 1)
State ATHR-180M 1 (STHR-180X3 1) is a gas tankless water heater from State rated 5.3 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 | 5.3 GPM |
|---|---|
| Draw pattern | High |
| Minimum activation flow | 1 GPM |
| Gas input rate | 180 kBTU/h |
|---|
| Max current draw | 5 A |
|---|---|
| Vent type | Power Vent, Power Direct 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 State ATHR-180M 1 (STHR-180X3 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) | 5.3 GPM | 2 |
| 55 °F | Mild climate (~65 °F groundwater) | 5.3 GPM | 2 |
| 70 °F | Cold climate (~50 °F groundwater) | 4.9 GPM | 2 |
| 77 °F | DOE test condition | 4.4 GPM | 2 |
Similar water heaters
- A. O. Smith ATHR-180M 1 (UEF 0.95)
- A. O. Smith ATHR-180M 1 (ATHR-180X3 1) (UEF 0.95)
- A. O. Smith ATHR-180M 1 (GT15THR-180M 1) (UEF 0.95)
- A. O. Smith ATHR-180M 1 (GT15THR-180X3 1) (UEF 0.95)
- American ATHR-180M 1 (MTHR-180M 1) (UEF 0.95)
- American ATHR-180M 1 (MTHR-180X3 1) (UEF 0.95)
Frequently asked questions
Is the State ATHR-180M 1 (STHR-180X3 1) ENERGY STAR certified?
Yes, the State ATHR-180M 1 (STHR-180X3 1) holds a current ENERGY STAR certification for water heating efficiency (UEF 0.95).
How much does the State ATHR-180M 1 (STHR-180X3 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 State ATHR-180M 1 (STHR-180X3 1) use?
The State ATHR-180M 1 (STHR-180X3 1) uses Power Vent, Power Direct Vent venting with 3 / 2 in vent connections. Matching the existing vent type is usually the cheapest replacement path.
Is the State ATHR-180M 1 (STHR-180X3 1) a smart water heater?
No, the State ATHR-180M 1 (STHR-180X3 1) is not connected-capable — it has no app connectivity or demand-response support.
Sources
- data.energystar.gov (retrieved 2026-07-17)