Rinnai RE140e
#17 in GasFull review
A good outdoor heater for a one or two bathroom home in a mild climate.
Amazon $884.10 Amazon $884.10$884.10
The Rinnai RE140e rates 3.3 among gas tankless water heaters; the Bosch Tronic 6100 C 27 rates 3.1 among electric ones. The Bosch Tronic 6100 C 27 costs $247.50 less ($636.60 vs $884.10).
Bosch Tronic 6100 C 27
#10 in ElectricFull review
For a two bathroom home in a warm climate that wants a compact whole home heater with a 2 year parts warranty, double what Rheem gives.
Amazon $636.60$636.60
Prices were last checked October 31, 2026 and are subject to change; the price and availability shown by the retailer at the time of purchase apply.
Scores side by side
These two sit in different fuel classes (gas and electric), and each is scored against the reference points for its own class, so a rating says how well each does among its own fuel peers. How we rank explains each factor.
| Factor weight | Rinnai RE140e | Bosch Tronic 6100 C 27 |
|---|---|---|
| Overall rating | 3.3/5 | 3.1/5 |
| Value 35% | 58 $6.32 per 1,000 BTU/h ($884.10, 140,000 BTU/h) | 49 $23.58 per kW ($636.60, 27 kW) |
| Heating power 25% | 25 140,000 BTU/h | 64 27 kW |
| Efficiency 15% | 6 0.81 UEF | 38 0.93 UEF |
| Warranty 25% | 100 15-year heat exchanger warranty | 29 5-year heat exchanger warranty |
Specifications
| Rinnai RE140e | Bosch Tronic 6100 C 27 | |
|---|---|---|
| Heating | ||
| Fuel | Gas | Electric |
| Gas type | Natural gas or propane | - |
| Gas input | 10,400 to 140,000 BTU/h | - |
| Electric power | - | 27 kW |
| Max flow | 5.3 GPM | 5.3 GPM |
| UEF | 0.81 | 0.93 |
| Condensing | No | - |
| ENERGY STAR | No | - |
| Installation | ||
| Venting | Outdoor | - |
| Voltage | - | 240 V |
| Breakers | - | 120 A total |
| Weight | 38.3 lb | 14.8 lb |
| Features | ||
| Built-in recirculation | No | No |
| Wi-Fi | No | No |
| Heat exchanger warranty | 15 years | 5 years |
| Parts warranty | 5 years | 2 years |
| Released | - | 2023-01 |