Something interfering with your Broadband service, but you can't put your finger on what? You may be affected by electrical interference, read on to find out more.

What is REIN and SHINE?

Repetitive Electrical Impulse Noise (REIN) and Single Isolated Impulse Noise (SHINE) describe interference that can affect the stability and performance of a Broadband service.

In both cases, a power source is generating interference in the frequencies used by the service.

REIN is where this interference is generated for the duration of use of an electrical device and will typically result in disconnections or line errors while the device is in use. At its most extreme, REIN may prevent any connection being established at all.


SHINE is where this interference is generated as a burst – when a device is powered on or off, for example. As a result, disconnections or line errors may result at the time a device is switched on or off.

What are the effects of REIN and SHINE on my Broadband service?

In addition to the disconnections caused by REIN or SHINE you are likely to see a slower speed due to line errors and BT’s automated systems working to counteract the symptoms by restricting the maximum speed you can connect at. Lowering the speed creates a “buffer” to the interference, so it doesn’t cause your connection to drop.

Example causes of REIN and SHINE

Many electrical devices could be responsible for causing REIN and SHINE that affects your Broadband service. Below is a list of some example sources, however many electrical devices have the potential to cause REIN or SHINE:


·        Faulty power adapters.

·        Timed devices, such as central heating.

·        Christmas tree lights (especially on ‘flash’ setting).

·        EPOS and PDQ devices.

·        Railway power lines.

·        Streetlights.

·        Roadworks.

·        Faulty set-top boxes, televisions and other appliances.

·       Power cables running close to telephone wiring in the home.

For more information contact us on 0191 4198181 or email