@Gary_66 the alarm light on older ONT units is triggered by the failure of the built-in battery back up unit which these units included to allow a digital phone connection during a power failure. This facility was never used in practice and newer units dont have the battery at all . It is therefore safe to ignore but if it annoys raise it with Sky as it can be bypassed or a newer unit fitted.
A red LOS light however indicates a fault.
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65inch Sky Glass, 3 Sky Streaming Pucks, Sky Ultrafast + and Sky SR213(white Wifi Max hub) main Wifi from 3 TP-Link Deco M4 units in access point mode
