topic Re: Moving into a new build - ONT Box not connected correctly? in Broadband

Moving into a new build - ONT Box not connected correctly?

tommomate — Fri, 01 May 2026 09:07:07 GMT

Hi all,

I’m moving into a new build on 8th May and Sky have told me the FTTP broadband should be plug and play.

During the home tour, the person showing me around said he didn’t think the Openreach kit had been fitted properly. Looking at the ONT, I can’t see the green fibre cable going into it like I’ve seen in other examples. It looks like the green connector/cable may be loose or hanging down instead.

I’ve attached a photo for reference.

Does this look properly installed, or does it look like the fibre isn’t connected into the ONT yet?

Also, should I be chasing Sky about this before activation, or is this something Openreach would need to sort?

I’m trying to avoid moving in and finding out the broadband can’t go live because the ONT wasn’t fully connected/tested.

Thanks.

Re: Moving into a new build - ONT Box not connected correctly?

TimmyBGood — Fri, 01 May 2026 09:46:20 GMT

@tommomate

I'd say those green optical jacks are the incoming fibre pigtails and have simply been unplugged from the boxes above them.

Replugging is trivial but don't kink the cable.

Re: Moving into a new build - ONT Box not connected correctly?

TimmyBGood — Fri, 01 May 2026 09:45:20 GMT

@tommomate

Perhaps more importantly, both ONTs are missing their power supplies.

Re: Moving into a new build - ONT Box not connected correctly?

tommomate — Fri, 01 May 2026 09:47:34 GMT

So the green and white cables just need to be plugged into the bottom of the box on the left?

Re: Moving into a new build - ONT Box not connected correctly?

TimmyBGood — Fri, 01 May 2026 09:57:37 GMT

@tommomate

The green jack below the Openreach ONT should be plugged into it.

The other one appears to be fibre from a different supplier and belongs to the other ONT.

You'll need to locate power supply plugs and cables before they can deliver broadband.

Re: Moving into a new build - ONT Box not connected correctly?

tommomate — Fri, 01 May 2026 09:51:29 GMT

So plug the cable thats undeneath it in, plug the ethernet cable from the router WAN into the bottom of the ONT box and it should work?

I thougtht the ONT box was meant to have 3 cables into it?

Re: Moving into a new build - ONT Box not connected correctly?

TimmyBGood — Fri, 01 May 2026 10:01:50 GMT

@tommomate wrote:

I thougtht the ONT box was meant to have 3 cables into it?

You need to find the power supply plug.

This or something similar.

Re: Moving into a new build - ONT Box not connected correctly?

Chrisee — Fri, 01 May 2026 09:58:27 GMT

@tommomate it does the Fibre feed, the power supply and an ethernet cable to connect the hub which comes in the hub's packaging.

Re: Moving into a new build - ONT Box not connected correctly?

tommomate — Fri, 01 May 2026 10:11:16 GMT

So i dont need an engineer to come out or anything like that?

Re: Moving into a new build - ONT Box not connected correctly?

tommomate — Fri, 01 May 2026 10:11:46 GMT

so that green cable on the right needs to be plugged into the bottom of the openreach box on the left hand side?

Re: Moving into a new build - ONT Box not connected correctly?

Chrisee — Fri, 01 May 2026 10:27:56 GMT

@tommomate the photograph isnt thst good but the green fibre feed looks that it could be for the ONT on the right as the property looks to have two potential fibre feeds. However the green cable does look like similar to the fibre pigtail Openreach used on my install.

The reason why no engineer is booked is that the Openreach database indicates an ONT us in place. You can only know if it works or not after the service is activated. If it fails, e.g because the power supply is missing, Sky will book an engineer but they can't do that in advance. All home moves particularly into new builds have risks so hedge your bets hope for the best but plan for the worst.

Re: Moving into a new build - ONT Box not connected correctly?

TimmyBGood — Fri, 01 May 2026 10:40:20 GMT

@tommomate wrote:

so that green cable on the right needs to be plugged into the bottom of the openreach box on the left hand side?

You appear to have two ONTs and two optical pigtail cables.

Each pigtail needs to be plugged into its own corresponding ONT.

Each ONT requires its own power supply to function