If you're having trouble connecting to the control box and there's no Bluetooth symbol showing, work through the steps below.
Check the app's Bluetooth permission
The most common cause is the Grainfather app not having permission to use Bluetooth on your device.
- Go to the Settings menu on your device.
- Find and select the Grainfather app listing.
- Look for a prompt or toggle that says "Allow Grainfather to access Bluetooth."
- Make sure the Bluetooth setting is checked/enabled.
Check that Bluetooth is switched on at the device level
Separate from app permissions, confirm Bluetooth itself is turned on:
- Open your device's Quick Settings or Settings > Bluetooth.
- Make sure it's toggled on, not just app-level permissions.
- If it was already on, try toggling it off and back on — this can clear a stuck connection state.
Restart the Grainfather app
Fully close the app (not just minimise it) and reopen it. This can resolve the symbol failing to appear after a permissions change.
Check your distance from the unit
Bluetooth has a limited range. Make sure your device is reasonably close to the control box — move closer and try again if you were further away.
Still not showing?
If you've checked permissions, confirmed Bluetooth is on, restarted the app, and you're within range — and the symbol still isn't appearing, get in touch with the Grainfather Customer Service Team for further help.