A developer has created a clever solution to the common problem of not knowing how much hot water remains in a storage water heater. Using a Shelly 2PM Gen4 smart relay, they implemented a script that estimates water volume and remaining hot water based on power consumption patterns, without any physical modification to the heater. This approach leverages the device's built-in scripting capabilities to monitor energy usage and infer water temperature and volume. The project demonstrates how modern IoT relays can transform traditional appliances into smart devices with minimal effort. For developers and hardware hackers, this is a practical example of using edge computing for home automation. The technique could be extended to other appliances like boilers or heat pumps, making it a valuable signal for the smart home community.
A developer uses Shelly 2PM Gen4 to predict water heater hot water remaining without modifying the appliance. This showcases how programmable relays can turn dumb appliances into smart ones with simple scripting.