The garage door is probably the automation with the best ratio of cost to use: it opens several times a day, every day, and the remote gets left indoors with remarkable frequency.
The good news is that almost no motor needs opening up: nearly all of them already allow for exactly this.
The idea: imitate the button, not replace the motor
Every garage door control board has an input for the wall button: two terminals that, closed together, make the door move. They carry no useful voltage, they are just waiting for a contact.
The Shelly wires in there and does exactly that: closes the circuit for a moment, just as a finger on the button would. The motor cannot tell the difference, which is why the remote and the wall button go on working as before. You are not replacing anything, you are adding one more way to give the order.
Which models work
Any with a dry-contact output: Shelly 1 Plus, Shelly Plus 1 Mini, Shelly 1 Gen3 or Shelly 1 Gen4 — the last adding Matter and Zigbee.
The same warning applies as in opening the street door from your phone: the PM models put voltage on the output, not a free contact. They are not for this.
The advantage almost nobody uses: the board’s own 12 V
These models accept 12 V DC, 24-48 V DC and 110-240 V AC. And it turns out most control boards already have 12 V DC available for powering accessories.
That changes the job entirely: no running mains up to the garage ceiling, no hunting for a socket. You power the Shelly from the board itself and everything stays inside one enclosure. It is the difference between half an hour and an afternoon.
Step by step
- Cut the motor’s power before touching any cable. Not optional: a control board has 230 V inside even when the control side is low voltage.
- Find the control terminals. Usually marked PUSH, INPUT, START or similar. If you have a wall button, its two wires land right there — the most reliable clue.
- Connect the Shelly’s output to those two terminals, in parallel with the existing button.
- Power the Shelly, preferably from the board’s own 12 V if it has it.
- Set it to “momentary” mode before testing. This is the critical step.
“Momentary” mode is not a detail
In normal mode the relay stays closed until you tell it otherwise. To the control board that is somebody leaning on the button indefinitely, and no motor is designed for that.
In momentary mode the contact closes for an instant and releases itself. Set it before the first operation, not after seeing what happens.
Knowing whether it is open or closed
This basic build opens and closes, but it does not know the door’s state — it fires pulses blind. From your phone you cannot tell “open” from “close”.
A magnetic sensor on the Shelly’s I input fixes that. With it the device knows whether the door is shut, which unlocks the automations that are actually worth having: alert you if it has been open twenty minutes, or close it by itself after a while.
It is optional, and in practice it is what turns this from a toy into something useful.
Before you automate closing, think it through
A garage door is heavy. If you are going to close it automatically, make sure the motor’s safety systems are in place and working — photocells, obstacle detection. That check is part of the job, not an extra.
The console shows the device’s state and its connection history, handy in a garage where Wi-Fi coverage is usually poor. The app and the console work with Gen2, Gen3 and Gen4.
How to use both, section by section: mobile app manual and web console manual.