RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1)
RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1) is a gas tankless water heater from RELIANCE WATER HEATERS rated 5.8 GPM at a 0.95 UEF.
| Uniform Energy Factor (UEF) | 0.95 |
|---|---|
| Annual gas use (natural gas) | 178 therms/yr |
| Annual propane use | 194.53 gal/yr |
| Fuel | 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 Vent |
| Vent size | 3 |
| Smart / connected capable | No |
|---|
| Height | 22 in |
|---|---|
| Width | 18 in |
| Depth | 11 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 RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1) 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 |
Similar water heaters
- A. O. Smith ACTH-199M-(N,P) 1 (UEF 0.95)
- 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)
Frequently asked questions
Is the RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1) ENERGY STAR certified?
Yes, the RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1) holds a current ENERGY STAR certification for water heating efficiency (UEF 0.95).
How much does the RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1) cost to run per year?
About $525 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 RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1) use?
The RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1) uses Power Vent venting with 3 in vent connections. Matching the existing vent type is usually the cheapest replacement path.
Is the RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1) a smart water heater?
No, the RELIANCE WATER HEATERS T-H3-OS-N 1 (TS-540-LEH 1-1) is not connected-capable — it has no app connectivity or demand-response support.
Sources
- data.energystar.gov (retrieved 2026-07-17)