- If you care about seeing the water temperature of your water heater, and the distance between the Sonoff device and the water tank is less than 5 meters, check out the Sonoff TH Elite 20A and the Sonoff temperature sensor.
- If you do not care about monitoring the temperature, than the Tongou eWeLink Smart Circuit Breaker 63A is the best choice. As a bonus, you also get to monitor the power used by the water heater.
