topic Re: ONT Fault in Broadband

ONT Fault

Bribhoy7 — Fri, 09 Jan 2026 19:09:46 GMT

Red fault light on ONT

Re: ONT Fault

Daniel0210 — Fri, 09 Jan 2026 19:13:43 GMT

@Bribhoy7

If you have an ONT box displaying a red light, see this further advice...

https://helpforum.sky.com/t5/Broadband-Talk/Can-t-connect-to-broadband-and-have-a-red-light-on-your-ONT/ba-p/5151861

Re: ONT Fault

Bribhoy7 — Fri, 09 Jan 2026 19:25:33 GMT

Thanks but I've done all of those steps by and still have a red fault light

Re: ONT Fault

Daniel0210 — Fri, 09 Jan 2026 19:26:58 GMT

@Bribhoy7

Have you checked the service checker?

Re: ONT Fault

Bribhoy7 — Fri, 09 Jan 2026 19:32:52 GMT

Yes, done everything, service checker says everything ok but on phone when they done a check it says there is a fault 🤷🏼

Re: ONT Fault

JimM1 — Fri, 09 Jan 2026 19:48:25 GMT

@Bribhoy7 It's time to change the FOUR rechargeable batteries in that BBU, that is all possibly wrong with it, see the link below for the video on how to change them!

BT Openreach Fibre ONT - How to replace Battery Backup Batteries for phone line

Re: ONT Fault

Bribhoy7 — Fri, 09 Jan 2026 20:00:43 GMT

Brill, thanks I will try that 👍🏻