Intermittent or slow broadband? Troubleshooting connection problems

Whether it's slow, intermittent, or not working at all, there are few things more frustrating than a dodgy broadband internet connection! They can make life very difficult and even cost money if you rely on internet for work. 

In this guide we’ll look at common faults which can affect broadband and phone lines, and help you troubleshoot these issues so you don’t have to wait in a queue for tech support.

Common causes of slow broadband

Other software and devices

If the broadband is significantly slower than usual the cause may be software or other devices connected to the network. Certain applications, especially file sharing software, can use a lot of bandwidth.

Traffic shaping

Traffic shaping, or traffic management, is used by internet service providers to control performance sometimes by prioritising tasks over others, or by slowing down especially demanding activity. It’s most likely to affect file sharing.

Not all ISPs use traffic management so if this is a problem you might want to consider a switch to a different internet provider.

Problems with sites and services

If a particular web site or service is being especially sluggish but everything else is normal then the problem almost certainly lies outside your broadband connection. In that situation the only thing to do is wait until it’s fixed.

Dodgy Wi-Fi

Wi-Fi is undoubtedly useful but it can often be the cause of slow broadband. Sometimes a fault will occur for no clear reason, but often it can be fixed by simply disconnecting and reconnecting Wi-Fi on the device or by restarting the router.

If it’s an ongoing issue it might be due to poor signal strength. Use Wi-Fi boosters to increase the range. Or the router could be old and lacking support for faster data transfer speeds, in which case upgrading to a newer model can provide improved speed and signal strength. If your router is supplied by the broadband provider speak to them about an upgrade.

Broadband line faults

Sometimes the broadband will be slow due a problem with the provider. If you eliminate all causes inside the home, try rebooting the router. If it continues, speak to the provider or check their online service status. This might be an issue with your connection that they can remedy, but if it’s a wider network problem there will be nothing to do but wait.

Common quick fixes

Is your broadband at fault?

Before doing anything else you need to identify where the problem lies. Is it a fault with your router or the broadband, or is it an issue with the service you’re trying to access or the device you’re using?

Try to access another web site or service, and if that doesn’t work use another computer or device. If you’re connected over Wi-Fi, try plugging a network cable into the router - if that works, the Wi-Fi may be the cause

If there is no internet activity at all after this, the problem lies with either the router or the broadband line itself.

Reset software and hardware

Switching it off and on again is a cliche, but it’s an easy fix which often works. Don’t jump straight to rebooting the router though. Try software, then computers and devices (including Wi-Fi boosters, powerline adapters or any networking kit) then the router. Be patient when power cycling your router as it can take several minutes to reconnect.

Remove new devices or applications

If the broadband has stopped after installing new hardware or software try removing or disabling the newcomer to see if that fixes the issue.

Check for data-hungry apps

Some software applications will use almost all available bandwidth and drastically slow down other activities. Prime culprits are large software updates, file sharing applications and software such as Steam, where file downloads can be very large.

Phone line faults

No dial tone

First check the obvious stuff. Is the telephone cable securely in the socket? If you’re using a cordless phone, do the batteries need replacing?

Next, remove all devices from all phone sockets then plug a phone directly into the master socket.

If there’s still no dial tone you can try accessing the test socket which is available on some phone points. If your faceplate looks like the one pictured here, the lower half of the faceplate can be unscrewed to get direct access to the test socket.

If there is still no dial tone, or you do not have an accessible test socket, contact the phone service provider.

If you do get a dial tone while connected to the test socket, the fault is with your internal wiring or equipment.

Noise on the line

Ensure all devices connected to the phone line have a micro-filter fitted (if the phone point is not pre-filtered). Check that the problem is not occurring only with one phone - this is a problem with the phone rather than the line. If it only happens when calling a particular number, it’s probably not a fault on your line.

As with dial tone issues, remove all other device connected to the phone points and plug into the test socket. If the line noise is still present speak to your phone service provider. If it’s gone, the problem is with the equipment or lines inside your home.

Slow broadband

Check what speed you should be getting

Use a speed test to check current performance. Shut down other devices connected to the router, and close any unnecessary software applications.

A speed estimate should have been provided when signing up to the broadband package. Rather than the “up to” figure that’s based on the maximum possible speed, this estimate is a far more accurate representation of the true performance.

If you cannot find a record of this, contact the ISP, as you will need it to confirm that the broadband is slower than it should be.

It's also worth noting you may be eligible for broadband compensation if your speeds are significantly lower than billed for an extended period.

Getting in touch with your provider

Our guide to broadband customer services and technical support contains contact details and links for many ISPs.

Useful tools

Broadband Genie speed test

Openreach network incident check

ISP service status links



John Lewis

Virgin Media