Evening Sean
You should first try the Quiet Line Test on your own phone a few times, to get experience of doing so.
There are NO costs for doing this!
There is a slight chance that the facility is not available on your phone or your mother's phone.
OPENREACH BT has only a legal obligation to maintain the line to simple telephone quality, NOT to Broadband requirements, hence having to test it by preferably a corded/old phone handset.
Plug that phone with an ADSL Splitter in to the BT Master Socket, usually hidden in a cupboard etc.
Dial 17070, wait for the Response.
Several Test Options will be offered.
Normally it is Option 2 (Dial 2); but with SKY, it is Option 4 (Dial 4).
The Line should either be silent or a very low hum.
If it is noisy, "Snap, Crackle and Pop", engineering tones similar to dial tones etc, then it should be reported to the Telephone Provider, ie the company that you/your mother pay the LINE RENTAL to.
And specifically NOT to OPENREACH BT.
The Line Provider may or may NOT be another part of BT; or may part of the Broadband package, so possibly SKY, EE, PlusNet etc.
Report it as a PHONE Problem, avoid mentioning Broadband; and in your mother's case, do NOT mention that she normally does not use it for conventional phone purposes.
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If you do NOT hear any noises etc at the Master Socket, then reconnect your internal wiring; and try the QL Test from each of the internal sockets, also trying with each Broadband item connected and disconnected.
Also switch ON and OFF other potential sources such as Plasma TV sets, microwave cookers, Christmas Lights etc.
If you hear any untoward noises during this stage, then it is your/your mother's responsibility to arrange remedial action, either by yourself or a knowledgible friend etc.
Specificallly it is NOT OPENREACH's responsibility.
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I acknowledge the difficulties with your mother being in Peterborough and yourself in North Wales; as I frequently have to deal remotely with technical problems from up here in the Kingdom of Fife, to down in Devon, Glamorgan and around Scotland.
BUT unless you have suitable contacts in Peterborough, there is no other free or cheap way of getting the situation sorted out.
And whatever you do arrange/arrive at, first practise on your own line, so that you have a clearer idea of what needs to be done in Peterborough.
If it is Line problems, not only are they affecting the present BB service; but they will continue to affect in varying degrees any future apparent "improvement" such as if you try different modem/routers; or moving to FTTC/VDSL;
Edited by deleted (Sun 29-Dec-13 07:49:56)