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 2.5. The Bosch Tronic 4000 C 10 leads on efficiency and value. The Bosch Tronic 4000 C 8 costs $22.99 less ($229 vs $251.99).
Bosch Tronic 4000 C 8
#18 in ElectricFull review
For instant hot water at a kitchen or bathroom sink far from the main heater.
Amazon $229$229
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 efficiency (0.95 UEF vs 0.92 UEF) and value ($24 per kW ($251.99, 10.5 kW) vs $26.94 per kW ($229, 8.5 kW)).
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 | Bosch Tronic 4000 C 8 |
|---|---|---|
| Overall rating | 2.8/5 | 2.5/5 |
| Value 35% | 48 $24 per kW ($251.99, 10.5 kW) | 39 $26.94 per kW ($229, 8.5 kW) |
| Heating power 25% | 0 10.5 kW | 0 8.5 kW |
| Efficiency 15% | 62 0.95 UEF | 25 0.92 UEF |
| Warranty 25% | 50 heat exchanger warranty not published (neutral score used) | 50 heat exchanger warranty not published (neutral score used) |
Specifications
| Bosch Tronic 4000 C 10 | Bosch Tronic 4000 C 8 | |
|---|---|---|
| Heating | ||
| Fuel | Electric | Electric |
| Electric power | 10.5 kW | 8.5 kW |
| Max flow | 2 GPM | 1.6 GPM |
| UEF | 0.95 | 0.92 |
| Installation | ||
| Voltage | 240 V | 240 V |
| Breakers | 50 A total | 40 A total |
| Weight | 4.4 lb | 4.4 lb |
| Features | ||
| Built-in recirculation | No | No |
| Wi-Fi | No | No |
| Released | 2023-01 | 2023-01 |