Hello there everyone!
I’ve used a Shelly 2.5 running esphome to automate my central heating and hot water, to replace an old Honeywell 7 day programmer. All working great!
Initially, I used the old programmer as a backwards compatible switch for both the heating and water via the programmer’s button overrides, which worked as expected. All the states in HA were correctly reflected.
I would now like to get the status of my two 240V thermostats instead on the Shelly’s two binary sensors so I can track the time it takes for the hot water/heating to reach temperature.
I have been trying to get this working, but the binary sensor keeps saying On when the thermostats aren’t sending 240v.
Taking a closer look at the inputs with my meter, I can see that they are floating around 16-17VAC when open and 240V when they are closed.
The strange thing is, the old programmer’s live 240V switch lines float much higher than this when off (78V and 44.5V respectively and even just over 100V) and yet the binary sensor always showed the correct value of “Off” until the button was turned on. It’s always reported the correct state when using the programmer as the switch both in the Shelly firmware and esphome.
I don’t understand why at an even lower voltage the binary sensor shows as “On” when really it should be “Off”.
I wouldn’t have thought that such a low voltage would set the HIGH state on the sensor, given that the programmer never does? What am I missing and is it possible to get the correct state from the binary sensors in esphome?