Dual-fuel water heaters (natural gas or propane)
Certified on both fuels — convertible with a manufacturer kit.
Data current as of July 18, 2026 · 165 certified units · source AHRI + ENERGY STAR + DOE CCMS
Highest UEF in this group
HTP PH100-80****
UEF 0.93 · 80 gal · $237 a year to run.
See installed costs →UEF (Uniform Energy Factor) is the DOE test rating — hot water delivered per unit of fuel or electricity, measured the same way across every fuel, so it is the one number that compares a gas tank to a heat pump.
The 20 highest-UEF of 165 certified units · 2 with a verified place to buy
| Brand & model | UEF | Capacity | Fuel | Annual cost | Buy |
|---|---|---|---|---|---|
| HTP PH100-80**** | 0.93 | 80 gal | Dual-fuel | $237 | Get quotes |
| A. O. SMITH GPCC-50X 1** | 0.90 | 50 gal | Dual-fuel | $245 | Get quotes |
| LOCHINVAR LHPCX-50L 1** | 0.90 | 50 gal | Dual-fuel | $245 | Get quotes |
| LOCHINVAR LHPCT-40L 1** | 0.90 | 40 gal | Dual-fuel | $245 | Get quotes |
| LOCHINVAR SWL100-035 2** | 0.90 | 34 gal | Dual-fuel | $245 | Get quotes |
| LOCHINVAR SWN100-035 2** | 0.90 | 34 gal | Dual-fuel | $245 | Get quotes |
| RELIANCE WATER HEATERS 9-40-YRPCS 1** | 0.90 | 40 gal | Dual-fuel | $245 | Get quotes |
| AMERICAN PCG82-40S50L 1** | 0.90 | 40 gal | Dual-fuel | $245 | Get quotes |
| STATE GP8-40-YRPCSL 1** | 0.90 | 40 gal | Dual-fuel | $245 | Get quotes |
| A. O. SMITH HPCT-40L 1** | 0.90 | 40 gal | Dual-fuel | $245 | Get quotes |
| RELIANCE WATER HEATERS 9-50-YXPCS 1** | 0.90 | 50 gal | Dual-fuel | $245 | Get quotes |
| AMERICAN PCG82-50S65L 1** | 0.90 | 50 gal | Dual-fuel | $245 | Get quotes |
| STATE GP8-50-YXPCSL 1** | 0.90 | 50 gal | Dual-fuel | $245 | Get quotes |
| A. O. SMITH HPCX-50L 1** | 0.90 | 50 gal | Dual-fuel | $245 | Get quotes |
| RUUD PROU G40-50U CD HE EC3 | 0.90 | 40 gal | Dual-fuel | $245 | Get quotes |
| RICHMOND 12GUH40-50F* | 0.90 | 40 gal | Dual-fuel | $245 | Get quotes |
| RUUD PROU G40-50* RU HE EC3 | 0.90 | 40 gal | Dual-fuel | $245 | Get quotes |
| RHEEM PROP G40-50* CN HE** | 0.90 | 40 gal | Dual-fuel | $245 | Buy |
| RHEEM PROP G40-50* RH HE EC3 | 0.90 | 40 gal | Dual-fuel | $245 | Buy |
| A. O. SMITH GPCC-40L 1** | 0.90 | 40 gal | Dual-fuel | $245 | Get quotes |
Showing the top 20 by UEF. All 165 certified units in this group are filterable in the full database — we rank here rather than dump, because a table nobody can read is not a resource.
UEF and capacity are certified values from AHRI / ENERGY STAR / DOE CCMS; annual running cost is computed by us from national energy prices — see methodology. A tankless unit is rated on flow (GPM) rather than gallons, because it stores nothing.