Comment by meichenf

I have an ESP8266 running a tiny webstack on my local wifi that is wired to a low voltage relay that turns on my hot water heater (tankless). Combined this with a Apple shortcut so I can tell Siri to turn on the device (send a post request to the unit). Basically just a hacked together system to avoid using Homekit. It's been running great for 6 years with no maintenance so no complaints.