DIAGNOSIS The bulb is too far from the bridge or another Hue bulb to join the Zigbee mesh network. Zigbee needs a strong signal to pair.
FIX Bring the new bulb physically close to the Hue Bridge for pairing.
- Screw the new bulb into a lamp and place that lamp within 10-15 feet of the bridge, with a clear line of sight.
- In the Hue app, go to Settings > Add light > Search. It should find it in under a minute.
- After it's added, you can move the lamp/bulb to its final location.
IF THAT DIDN'T WORK The bulb may be from a different Zigbee system (like from a store return). Use the Bluetooth option in the Hue app to connect to it first, then it will prompt you to transfer it to the bridge.
HEADS UP Metal lamp shades, mirrors, or large appliances between the bulb and bridge can block the Zigbee signal during pairing.