Every replacement below is a published model with verified specs. Savings calculated from EIA average energy prices.
Quick verdict
Fewest install changes
Rheem RTGH-95DVLN-3
1 install change
Lowest annual bill
Bradford White RE2HP50-1NCTT
$144/yr
Shortest unit
Takagi T-H3J-OS-N-1
22.5" tall
Your NPE-240S2 costs $239/yr. Every option below cuts that bill. See all condensing tankless models
What your current unit costs to operate
Annual$239/yr
10-year projection$2,390
Based on U.S. average energy rates (EIA). UEF 0.96.
Replacement options
Rheem RTGH-95DVLN-3
Condensing TanklessUEF 0.93 / ~$250/yr
UEF 0.93 vs 0.96, compact at 23 vs 27.4 inches tall
Operating cost is similar to your current unit ($11/yr more).
Install changes
- No venting required (your current unit has a vent)
- 4.4" shorter than your current unit
Takagi T-H3J-OS-N-1
Condensing TanklessUEF 0.95 / ~$242/yr
UEF 0.95 vs 0.96, compact at 22.5 vs 27.4 inches tall
Operating cost is similar to your current unit ($3/yr more).
Install changes
- Different venting: power vent (currently direct vent)
- 4.9" shorter than your current unit
Rheem PROPH50 T2 RH400-30
Heat PumpUEF 3.88 / ~$146/yr / 10-yr tank warranty
Switch to heat pump, UEF jumps from 0.96 to 3.88, requires tank space and 240V
Annual savings$93/yr
10-year savings$930
Install changes
- Requires 240V (your current unit is 120V)
- 30A breaker needed (currently 15A)
- No venting required (your current unit has a vent)
- 34.4" taller than your current unit
- 4.9" wider than your current unit
Bradford White RE2HP50-1NCTT
Heat PumpUEF 3.89 / ~$144/yr / 10-yr tank warranty
Switch to heat pump, UEF jumps from 0.96 to 3.89, compact 46.1-inch height
Annual savings$95/yr
10-year savings$950
Install changes
- Requires 240V (your current unit is 120V)
- No venting required (your current unit has a vent)
- 18.7" taller than your current unit
Side by side, the key differences.
Replacement comparison
| Spec | Your unit | RTGH-95DVLN-3 | T-H3J-OS-N-1 | PROPH50 T2 RH400-30 | RE2HP50-1NCTT |
|---|---|---|---|---|---|
| UEF | 0.96 | 0.93 | 0.95 | 3.88 | 3.89 |
| Annual Cost | $239/yr | $250/yr | $242/yr | $146/yr | $144/yr |
| Annual Savings | $-11/yr | $-3/yr | $93/yr | $95/yr | |
| Height | 27.4" | 23" | 22.5" | 61.8" | 46.1" |
| Width | 17.3" | 18" | 17.8" | 22.2" | 18.0" |
| Warranty | — | — | 10 yr | 10 yr |
● Best value in each row. Your unit column shows the model being replaced.
Common install considerations for gas tankless units
What is required depends on your existing installation, local code, and installer preference.
The federal tax credit of up to $2,000 under IRA Section 25C expired December 31, 2025. State and utility rebates may still apply.
Related
As an Amazon Associate I earn from qualifying purchases. RatingPlate may earn a commission when you use qualifying Amazon links. Links to Amazon are marked "(paid link)". We never display prices because Amazon prohibits showing prices outside their platform.
Sources. ENERGY STAR, manufacturer spec sheets, EIA average energy prices.Methodology