BoilerFaultCodesIdeal Override Green (flashing) Fault Code
Also written as OVERRIDEGREENFLASHING — same fault.
The Ideal Override Green (flashing) fault code means: your smart thermostat has lost connection with the boiler, causing it to enter a backup safety mode to ensure you aren't left without heat.. It appears on 1 Ideal model in our database.
Technical description: Failsafe active - Override and Failsafe only active when communication is lost between the Halo PRT and Smart Interface.
What causes the Ideal Override Green (flashing) fault?
This fault occurs when the wireless connection between your thermostat and the boiler's interface is interrupted or lost. The most common reasons are dead batteries in the wall unit, electronic interference from other household devices, or the thermostat being moved too far away from the boiler.
This issue is slightly more common in winter when homeowners move furniture or festive decorations that can accidentally block the wireless signal between the thermostat and the boiler.
DIY fix possible
Check if the Halo thermostat batteries need replacing.Ensure the Halo thermostat is within range of the boiler and has not been moved behind a metal object.Restart your internet router if the problem persists.Press and hold the override button on the boiler interface for 3 seconds to attempt a manual reconnect.
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Gas Safe Register →Ideal models that show the Override Green (flashing) fault code
Click a model for the full fault code list and model-specific repair notes.
Source
Ideal Override Green (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