how to know when the washing machine has finished
If you need to know when a device, like a dryer or washing machine has completed its work, get a ‘smart plug with energy monitoring‘. Amazon list many of them but whichever brand you get, check that it can be integrated with your home automation platform. For example TP-link has the HS110 with energy monitoring and it connects with Home Assistant. If yours is labelled Tuya / Smart Life / Sonoff there’s a good chance it works for this idea.
You just need a smart plug with energy monitoring
The idea is simple: leave the smart plug permanently switched on and the appliance plugged into it. Get your home automation software to monitor the current flowing via a routine / automation. The routine needs to wait until the current to the washing machine drops to a low level .
As far as I can imagine I can’t use the timer feature of a smart plug to turn on my washing machine. The washing machine needs an extra button press to start it after turning on. The smart plug CAN send me an alert when the cycle is finished and it CAN also total how much energy washing uses.
I don’t want my water immersion heater running all the day. I use a Sonoff POW2 (shown above) to switch off my water heater when the tank thermostat switches it off.
You can use an energy monitoring smart plug with an electric iron, or panini press or curling tongs to ensure that a device isn’t left switched on. You need to make a home automation (aka routine) that watches for high current and then turns off the smart plug after say, an hour.