Short answer: nine times out of ten it is not in inclusion mode when you press the button, or the device is still joined to a previous network.
Work through these in order:
- Put the hub in inclusion mode first, then press. The hub has to be listening before the device sends its join request. If you press first and then start inclusion, nothing happens.
- Triple-press the button on the plug. Quick presses, not a long hold. The status light starts blinking fast, which means the plug is broadcasting. On 700 and 800 series models the hub will then ask for the S2 PIN, which is the 5-digit code printed on the box.
- Watch the hub, not the light. The device is paired when it appears in the hub or app. The light returning to steady just means the outlet is switched on, not that pairing worked.
- Already joined to something else? Run exclusion first (hub in exclusion mode, triple-press the plug), then include again. A device that is still joined to an old hub will refuse a new one.
- Distance. Pair it on the same desk as the hub, then move it. Pairing through two walls and a metal appliance is the second most common failure.
If the light never blinks fast when you triple-press, the button sequence is not registering. Check your model’s manual, since a few older models use a different gesture.