ESPHome controls Haier water heaters through a local connection

ESPHome adds local control for Haier hOn water heaters by connecting to the appliance’s serial interface in place of its original Wi-Fi module. The implementation was tested on a Haier VH3W and controls power, operating mode and target temperature.

The connection checks the appliance every five seconds and can report its second temperature zone, estimated heating time and available hot water. A command is treated as complete only after the heater confirms it in a status message. Contributor TheLexus supplies the implementation and companion guide in their first contribution to ESPHome.