Ongoing Connection Dropouts Since Moving to Full Fibre

[#1]

Hi,

Since switching to Full Fibre towards the end of last year, I’ve been experiencing frequent and frustrating connection dropouts. These outages range from a few minutes to several days and have occurred at least ten times this year—typically every week or two.

Each time this happens, I contact Plusnet support and go through the same troubleshooting steps, which is becoming increasingly tedious and unproductive. So far, I’ve had three engineer visits (two from Plusnet, one from Openreach), all of whom confirmed there’s nothing wrong with the line. However, the Openreach engineer mentioned a known issue with certain ONT boxes not reconnecting properly—a problem apparently affecting thousands of users. He also noted there’s currently no timeline for a fix. When I asked Plusnet about this, they claimed to have no knowledge of such an issue, leaving me unsure who to believe.

In my case, the only reliable way to restore the connection seems to be physically powering down all equipment, unplugging the Ethernet cable from the ONT box, waiting ten minutes, and then rebooting everything. This usually resolves the issue temporarily.

For context, I’m not using the Hub 2—my setup uses an Orbi mesh system connected directly to the ONT box, which is very stable around 95% of the time, aside from these recurring connection issues. Unfortunately, Plusnet support hasn’t been helpful. For example, the most recent support call involved someone insisting I change my password, which clearly has no bearing on the problem.

I work full time from home and have lost significant time and productivity because of this ongoing issue. I’m now at a loss as to what to do.

My questions are:

• Is there a confirmed issue with certain ONT boxes not re-establishing connections?

• Should Plusnet or Openreach be doing more to investigate and resolve this?

• Could this issue be caused by my setup, even though it’s otherwise stable?

• Is there any link to ongoing network works in the area?

Any clarity or support you can provide would be greatly appreciated—I can’t continue with such an unreliable connection.

[#2]

If this really is an ONT issue, then it falls into BT Openreach's domain, but will required drive from Plusnet.  @bobpullen - is there anything on your radar please?

Not using the supplier PN Hub Two adds complications in that there is some possibility that the issue is between the ONT and your third-party device.  That puts responsibility with the third-party device supplier.

When you encounter these issues, what is the status of the lights on the ONT?

Can you use the Hub Two as a means of eliminating the possibility of third-party device issues and move you into a Plusnet fully supported configuration.

In passing, do note that WFH is not permitted within Plusnet's T&Cs for their residential grade service.

[#3]

I do believe the ONT box lights are the same as usual but I will double check again next time it goes down n the next week or two! I can use the Plusnet Hub 2 as a trial but when I have been on the phone before and been made to switch to the Hub 2 the same problems persist and I am told to just "wait" for it to resync.

I can't see anywhere in the terms and conditions https://www.plus.net/help/legal/terms/ that states that I cannot use my internet to work from home? Would seem a strange thing to have in there in 2025 and with no Plusnet Business offering anymore.

[#4]

Hi Stuart,

If there is no red light on the ONT, then the fibre level connection will not have dropped out.  Something could have interrupted the PPP session.  Is there any diagnostic information in your network devices.

T&Cs see ... Terms and conditions for Plusnet residential services | Help | Plusnet (service use)

2. Your use of the services

2.1. You must:

2.1.3. use the services for personal use in the UK (so don't use the services to run your own business, but a couple of work emails or occasional home working are okay) and in accordance with our Acceptable Use Policy;

Emphasis added.

[#5]

Switch to ISP if Plusnet won't help you. You have the full rights to leave because of continue issues say the engineer 'Openreach engineer mentioned a known issue with certain ONT boxes not reconnecting properly—a problem apparently affecting thousands of users. He also noted there’s currently no timeline for a fix'.

[#6]

That’s not an answer reflecting common sense.  If this is an ONT issue, changing ISP is not going to change the characteristic of the ONT unless an alternative ISP can supply via an altnet infrastructure.

Do not know how valid the claims are here - https://www.ispreview.co.uk/talk/threads/ont-issues-with-zen-business-fibre-900.42072/ - but the discussion sounds similar, except it’s a different ISP using the same BT infrastructure.

[#7]

Yes that sounds like the exact problem that I have, OpenReach were certainly not keen on replacing my ONT and unclear if this would resolve the issue anyway. I will start loggng when the faults occur and see if there is a pattern.

[#8]

@bobpullen 

Is there anything in network diagnostic history which might assist here.  PPP radius history ... or something lower level?

There have been a few suggestions that fibre connections have been 'flaky', the OP states that a BTOR engineer suggested there are issues with ONTs and there is the above reference to similar with a Zen customer.  Is there any industry intel on this matter?

[#9]

Down again today, went offline at 12.30am, so about to go through the same old rigmarole of powering off and unplugging everything. Started keeping a log.

[#10]

@stuartjsmith 

With the ONT did you check the status of the lights?

Are you using the Hub two now? what was the colour of the light?

The Hub two has a log file are you able to attach a copy to this thread?

From the Home page navigate >Advanced Settings >Technical log >Event log click on Export.

This will create a .CSV file the result will be in the download folder.

If you are not using the Hub two does you current router have a log file? If so attach that.

Attach using the paper clip below the reply window.

EDIT: do not perform a factory reset of the Hub two as that deletes the event log

[#11]

Ok few questions to get through. I don't have logs because I didn't have debug logging turned on, I have turned this on today now (I am back to using my own router as the Plusnet Hub2 does not reach across the whole house). I have a video showing the ONT which I have attached (please don't comment on my mucky skirting boards!)

It went down again last night, at around 1am. What is very interesting is that DownDetector for the last two outages I have had show a lot of reports for Plusnet being down at the exact time by internet goes offline (and then does not come back up). So my internet is going down at the exact same time as many other people, and not coming back up until I fully reset the ONT (simply resetting the router does not work).

[#12]

Overnight maintenance often occurs after midnight  which might account for the 01:00 timing of the down messages. Be interesting what the log file comes reveals.

I would also look at other Comms Providers who use Openreach infrastructure as they may also reveal  peaks at that time.

Is the connection recovering or do you have do to take any action and if so what? A simple power off should all be required

[#13]

The connection is not recovering and this is happening every 1-2 weeks. Yes it is a simple switch off and on again (and I have been advised to remove the cables from the ONT box as it has battery backup), and this whole process takes me 15 mins and I am back. This however is not very helpful when it happens in the middle of the day, which it has frequently, when I am about to start doing some work for the day, meaning a delay, or when I am not there, as all my cameras etc go offline. I have lived with it since December now, it is very frequent, and there appears to be no resolution. The ONT box is not reconnecting after routine maintenance it would seem.

[#14]

@bobpullen - gentle nudge.  Is there a recognised profile for the reported perceptions discussed on this thread please?

[#15]

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@stuartjsmith wrote:

The connection is not recovering and this is happening every 1-2 weeks. Yes it is a simple switch off and on again (and I have been advised to remove the cables from the ONT box as it has battery backup),

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Your install is a new one. In a normal OR install there is no battery back up. Who put the BBU in and what type is it

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@stuartjsmith wrote:

 I have lived with it since December now, it is very frequent, and there appears to be no resolution. The ONT box is not reconnecting after routine maintenance it would seem.

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We badly need logs, bob and others can't help without those. So you are saying two routers will not reconnect after an issue?

How is the bbu connected - direct to a wall socket or an extension lead, same q regarding the router.

Can you connect the ont direct to the mains the supplied power brick..