BoilerFaultCodesIdeal Zigbee Red (flashing) Fault Code
Also written as ZIGBEEREDFLASHING — same fault.
The Ideal Zigbee Red (flashing) fault code means: your smart thermostat is currently in pairing mode and is searching for a connection to your heating system or internet gateway.. It appears on 1 Ideal model in our database.
Technical description: Pairing
What causes the Ideal Zigbee Red (flashing) fault?
A flashing red Zigbee light indicates that the thermostat or wiring centre has been manually put into pairing mode or has lost its existing link and is actively searching for a connection. This is typically triggered during the initial setup, after a power cut, or if the wireless signal between the devices has been interrupted for an extended period. It is not an internal mechanical failure but rather a communication state where the device is waiting to sync with your heating system.
DIY fix possible
Ensure your Smart Interface (connected to the boiler) is also in pairing mode.Follow the on-screen instructions on your Halo thermostat to complete the setup.Wait up to 2 minutes for the light to turn solid green, indicating a successful connection.
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Gas Safe Register →Ideal models that show the Zigbee Red (flashing) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal Zigbee Red (flashing) fault code information on this page is sourced and cross-checked against the official Ideal service / installation manuals for each affected model.
Reviewed by the BoilerFaultCodes Editorial Team · Last reviewed 27 April 2026