Bosch Tronic 4000 C 10
#15 in ElectricFull review
For a busy kitchen sink or a pair of sinks that need more flow than a small point of use heater gives.
Amazon $251.99$251.99
The Bosch Tronic 4000 C 10 is the better tankless water heater overall, rated 2.8 to 2.4. The Bosch Tronic 4000 C 10 leads on value and efficiency. The Rheem RTEX-06T costs $62.99 less ($189 vs $251.99).
Rheem RTEX-06T
#20 in ElectricFull review
For instant hot water at a single bathroom or kitchen sink on a budget.
Amazon $189$189
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.
Which should you buy?
- Choose the Bosch Tronic 4000 C 10 for value ($24 per kW ($251.99, 10.5 kW) vs $29.08 per kW ($189, 6.5 kW)) and efficiency (0.95 UEF vs 0.94 UEF).
Scores side by side
Each factor is scored 0-100 against the same fixed reference points for every electric tankless water heater; a clear win is highlighted. How we rank explains each one.
| Factor weight | Bosch Tronic 4000 C 10 | Rheem RTEX-06T |
|---|---|---|
| Overall rating | 2.8/5 | 2.4/5 |
| Value 35% | 48 $24 per kW ($251.99, 10.5 kW) | 33 $29.08 per kW ($189, 6.5 kW) |
| Heating power 25% | 0 10.5 kW | 0 6.5 kW |
| Efficiency 15% | 62 0.95 UEF | 50 0.94 UEF |
| Warranty 25% | 50 heat exchanger warranty not published (neutral score used) | 29 5-year heat exchanger warranty |
Specifications
| Bosch Tronic 4000 C 10 | Rheem RTEX-06T | |
|---|---|---|
| Heating | ||
| Fuel | Electric | Electric |
| Electric power | 10.5 kW | 6.5 kW |
| Max flow | 2 GPM | 1.6 GPM |
| UEF | 0.95 | 0.94 |
| Installation | ||
| Voltage | 240 V | 240 V |
| Breakers | 50 A total | 30 A total |
| Weight | 4.4 lb | 4 lb |
| Features | ||
| Built-in recirculation | No | No |
| Wi-Fi | No | No |
| Heat exchanger warranty | - | 5 years |
| Parts warranty | - | 1 year |
| Released | 2023-01 | - |