I live in a rental home with a three-stop dumb waiter. Each stop has a button that calls the dumbwaiter. I load my groceries in the garage, walk up two tall staircases, hit the top floor button, and have to wait three minutes for the dumbwaiter to arrive. I would like to replace the buttons with a smart button (Wi-fi or Z-wave) that will allow HA to send the dumbwaiter to another floor.
Any advice?
Hi @joelamkin - welcome to the forum.
If you have a Zigbee network already, something like a FingerBot or a SwitchBot device might do the trick - if the button is easy enough to push for the device.
As an alternative you could probably use an ESP-powered relay, but that would be much more effort - and maybe a space and design issue (with the relay not fitting into the small space and/or cables coming out from under the wall plate) 
Thank you! I was not aware of those physical button pushers. I’ll give one a try if I can’t find a replacement button.
It seems to me that something like a garage door opener might work, as it only needs to momentarily complete the circuit to make the elevator operate. Do you know of a hardwired simple button that only completes a circuit when pressed, but that can also be controlled by Home Assistant?
For a garage-door-opener like solution you’d probably still need something with a relay to close the circuit for a moment which I’d only know how to do with an esp-like device - and that would require wires additional wires coming out from under the button cover and would not run on batteries for long, i.e. it would need mains power as well.
Not sure about your house, but in mine that would get a WAF Score of sub-0 
Here’s one I’ve used in the garage in the past
And how would you power these devices?
It would be way better to find the control board where all those 3 buttons are actually wired. There you can add esphome devboard (or smart switch) in parallel with the original buttons.
What the 2 posts above me said. You need to find your control box, determine the voltages being passed to press the button, then wire everything in parallel so you can still use the old buttons on each floor.
You’re basically looking at a simple circuit with an ESP board (if you have 5v available) with either dry-contact relays or an optocoupler board.
I like the idea about going to the control box and using e.g. one of the 4 channel relays that are available for ‘a dime a dozen’ on Amazon or AliExpress.
Most of them even have physical buttons to press - if the control box is in the garage, instead of having to take a mobile out of the pocket - and can be set up for inching.
For many of these solutions, it all depends on wireless coverage, though.
You can work around that by either getting an ethernet esp board or a powerline WiFi adapter (assuming you’re on the same circuit) 
