Depending on the age of your dryer and how deep into the weeds you want to get, you might be able to use the closing of dry contacts on a door window sensor. My dryer is quite old and has a start button that, when pushed, engages contacts that are held on by an electromagnet. This is the 120v circuit in the dryer (all the electric dryers have a 240v circuit, and a 120v circuit internally).
I added a 120v relay to the power for the electromagnet on the start button. So when I press start on the dryer, the power going to the electromagnet also engages the 120v relay, thus opening contacts with no voltage on them. These are connected to the door/window sensor reed switch, which indicates āclosedā in HE. When the dryer stops, the relay turns off, closing itās contacts, and the door/window sensor indicates āopenā, which triggers my rule that the dryer is done (after a 1 minute delay).
The other way that works really well is the Homeseer status light sensor
I use this for my Bosch washer which is 220v and doesnāt vibrate at all. I used to just use an Aeotec Home Energy Monitor with it, but this washer is too efficient and was often too hard for it to distinguish running, from pausing mid-cycle, to just fluctuations on the line while it was off but still drawing a little power. Since adding the Homeseer status light detector, I have no false positives in the washer status.
The light sensor is designed to affix in front of a status light on the front of your machine, but I was able to mount mine inside the machine because the running light can be seen from inside too. Itās a cool device and can even distinguish blinking from solid and off. Thatās perfect because if you pause my washer, the light flashes. While itās running, itās solid, and once it stops, the light turns off. Perfect device for the use case.
