EcoSmart ECO 11
#5 in ElectricFull review
For a single shower or a pair of sinks in a warm climate, with a lifetime warranty if a pro installs it.
Amazon $244.78$244.78
The EcoSmart ECO 11 is the better tankless water heater overall, rated 3.4 to 2.4. The EcoSmart ECO 11 leads on warranty, value and heating power. The EcoSmart ECO 11 costs $24.21 less ($244.78 vs $268.99).
Rheem RTEX-11
#19 in ElectricFull review
For a single shower or a pair of sinks in a warm climate. The EcoSmart ECO 11 costs less and carries a lifetime warranty.
Amazon $268.99$268.99
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 EcoSmart ECO 11 for warranty (limited lifetime heat exchanger warranty vs 5-year heat exchanger warranty), value ($18.83 per kW ($244.78, 13 kW) vs $24.45 per kW ($268.99, 11 kW)) and heating power (13 kW vs 11 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 | EcoSmart ECO 11 | Rheem RTEX-11 |
|---|---|---|
| Overall rating | 3.4/5 | 2.4/5 |
| Value 35% | 66 $18.83 per kW ($244.78, 13 kW) | 46 $24.45 per kW ($268.99, 11 kW) |
| Heating power 25% | 8 13 kW | 0 11 kW |
| Efficiency 15% | 25 0.92 UEF | 25 0.92 UEF |
| Warranty 25% | 100 limited lifetime heat exchanger warranty | 29 5-year heat exchanger warranty |
Specifications
| EcoSmart ECO 11 | Rheem RTEX-11 | |
|---|---|---|
| Heating | ||
| Fuel | Electric | Electric |
| Electric power | 13 kW | 11 kW |
| Max flow | 3.2 GPM | 2.7 GPM |
| UEF | 0.92 | 0.92 |
| Installation | ||
| Voltage | 240 V | 240 V |
| Breakers | 60 A total | 50 A total |
| Weight | 6.5 lb | 6.5 lb |
| Features | ||
| Built-in recirculation | No | No |
| Wi-Fi | No | No |
| Heat exchanger warranty | Limited lifetime | 5 years |
| Parts warranty | - | 1 year |