Performing a Quiet Line Test


Aim of this article:

This article provides instructions for performing a quiet line test to identify if there is 'noise' on a telephone line causing a fault.  If noise is present it can affect the quality of telephone calls as well as Broadband performance and reliability; resulting in slow speeds and connection drops.

Note: Noise on your line is classified as a telephone service fault, not a Broadband fault, so cannot be resolved by Zen Internet, unless you also pay for the Zen Talk service from us.
If you are affected by noise on your telephone line you will need to report it to your telephone service provider in order for the fault to be resolved first - a Broadband fault cannot be raised until the line noise has been fixed.


Before starting:

  • You should use a wired telephone connected to your BT test socket.  This guide shows you how to access the test socket.
  • Ensure you have a method of noting the date, time and results of the test (i.e. pen and paper/computer).


Performing the Quiet Line Test:

  1. Once you have your telephone connected to the BT test socket dial 17070.  You will reach BT's line test facility.
  2. Choose option 2 from the menu presented - "Quiet Line Test".
  3. If your telephone has the option, put it on mute.  You should hear nothing through the handset.
  4. If you do hear any line noise, crackling, buzzing, popping or humming, note the time when you conducted the test.
  5. Repeat the test several hours later to determine if the noise is present - again noting the time.  If no noise is present this time repeat the test at different times, noting if and when the noise is present.
    Note: Faults of this kind are caused by a number of different factors - including some that may only occur at particular parts of the day (e.g. when it's light or when it's dark) or during different kinds of weather (windy, rain, storms etc.).  Recording this additional detail may also help with your telephone service provider's investigations.
  6. Once you have identified the times when noise occurs contact your telephone service to report a fault.
  7. Keep hold of the record of the times tested throughout the duration of the fault, to ensure any work by your telephone service provider looks at any specific times when the problem occurs.

If you experienced problems with your Broadband service, and a noise fault has been fixed by your telephone service provider, monitor the Broadband connection for around 24 hours to ensure the service has a chance to adjust to the line working correctly.  If problems continue after this time refer to our Broadband troubleshooting guides for further advice.