Set up a Shelly device
Shelly is a small, affordable (~15 €) smart device that is installed next to your water heater, floor heating, or other electrical appliance. It connects the appliance to your WiFi network and Optimaatti controls it automatically based on electricity price.
What is Shelly?
Shelly is a WiFi-enabled switch device that is wired into the power line of the appliance you want to control (e.g. water heater). After that, Optimaatti can turn the appliance on and off automatically. You do not need to understand the technical details — it is enough that the device is installed and connected to WiFi.
What you need
- A Shelly device (e.g. Shelly Plus 1 or Shelly Plus 1PM). Price around 15–25 €. You can buy it from online stores.
- A WiFi network (the same network your phone is connected to) and its password.
- An Optimaatti account (register for free at app.optimaatti.fi) and the Optimaatti app. Newer Shellys are added directly with it over Bluetooth.
- The Shelly app on your phone only if you use the alternative Wi-Fi method (older devices). Available in App Store / Google Play.
Step 1: Install the Shelly device
Physical installation
The Shelly device is wired into the power line of the appliance you want to control. For example, if you are controlling a water heater, the Shelly is installed between the water heater's supply wire and the circuit breaker.
After this you should see
The Shelly device's LED light blinks or stays on, which means the device has power and is ready to be connected to WiFi.
Step 2: Connect Shelly to Optimaatti
Recommended: add with your phone over Bluetooth
Newer Shelly devices (Gen2, Gen3 and Gen4) are easiest to add directly with the Optimaatti app over Bluetooth. You do not need a separate Shelly app and you do not have to switch your phone's Wi-Fi network — the Wi-Fi credentials and the Optimaatti connection are set in one go.
- Open the Optimaatti app and start adding a new device.
- Choose "Add Shelly with your phone" (the Bluetooth method).
- Make sure the Shelly is powered and near your phone — the app finds it automatically.
- Pick the device from the list and enter your home Wi-Fi name and password.
- Press "Connect device". The Optimaatti connection is filled in automatically.
- The device reboots, joins Wi-Fi and appears in your device list in about 20 seconds.
Alternative: with the Shelly app (older devices)
If the device is not found over Bluetooth (for example an older Gen1 model), connect it to Wi-Fi with the Shelly app first, then add it to Optimaatti in step 3.
- Open the Shelly app on your phone.
- The app detects the new Shelly device automatically. Press "Add Device".
- Select your WiFi network and enter the password.
- Wait for the device to connect. This takes about 30 seconds.
After this you should see
With the Bluetooth method the device appears directly in your Optimaatti device list — you can skip to step 4. With the Shelly app method the device shows as connected in the Shelly app; then continue to step 3.
Step 3: Add device to Optimaatti
Add Shelly in the Optimaatti app
This step applies to the alternative Shelly app method. If you already added the device with Bluetooth in step 2, it is already in Optimaatti — you can skip to step 4.
- Open the Optimaatti app (in browser or on your phone).
- Go to Settings → Devices.
- Press "Add device".
- Optimaatti finds Shelly devices on the same network automatically. Select the device from the list.
- Give the device a clear name, for example "Water heater" or "Living room floor heating".
After this you should see
The device appears in the Optimaatti device list and you can turn it on/off from Optimaatti. The device is now ready for automation.
Step 4: Create your first automation
Creating an automation
- Open the device details in Optimaatti.
- Select what type of load the device controls (e.g. water heater, heating).
- Set the desired operating profile — for example "use cheapest electricity 6 hours per day".
- Save. Optimaatti starts controlling the device automatically.
After this you should see
The device status shows when Optimaatti turned it on and off. Electricity usage automatically shifts to the cheapest hours.
How do you know it all works?
- The Shelly device shows as green (connected) in the Optimaatti device list.
- You can turn the device on and off from Optimaatti.
- Automation is active and the device switches on during the cheapest hours.
- You can see from the device history when it was turned on.
What if something goes wrong?
What if Optimaatti cannot find the Shelly device?
Check that the Shelly device and your phone/computer are on the same WiFi network. You can test this by opening the Shelly app — if the device appears there, it is online. If the device does not appear anywhere, try restarting it by turning the power off and on.
What if the device appears but does not respond to control?
Make sure the device firmware is up to date (update in the Shelly app). Also check that the physical switch is not stuck in "always on" mode.
Do I need to understand device connection settings?
No. Optimaatti handles the connection to the Shelly device automatically. If Shelly settings show MQTT, that is just the technical name for the connection — you do not need to learn it.