Degraded service since moving to John Lewis as ISP (Supported by Plusnet of course!)

[#1]

OK, tried the self-help route and am amazed at the result I got - 15.5Mb/s at about 11:30 this morning.

Tried it exactly the same configuration this evening and getting between 3 &4 Mb/s, so as far as I'm concerned this proves my line is still capable of supporting the speeds I have historically seen. It's either the contention ratio or being throttled in the evenings - Not Happy!!

[#2]

Not ideal to be running speed tests with all those open tabs - facebook in particular is well known for pushing data down your connection, even if you are not looking at it.

You should just be running the BT speedtest and nothing else (as per instructions).

Before beginning the test, please ensure:

1. Your computer is plugged into the broadband line to be tested. This tester may not work on iPads/Tablets, smartphones or other mobile devices.
2. Your computer is directly connected to your modem/router via an Ethernet Connection (i.e. not via a wireless or powerline adapters).
3. Any wireless adapter in your computer is switched off.
4. Close any programs that may be running on your computer. This includes any background programs such as anti-virus software, corporate VPNs, peer2peer clients etc. (Please ensure you re-enable any anti-virus software after you have finished testing).
5. Reboot your modem/router by powering it off, waiting one minute, and then powering it up again. Wait for any lights on the router to stabilise before starting the test.
6. Restart your browser.
7. Ensure no other people or devices (e.g. broadband-connected TV set-top boxes) are using the broadband line to be tested.
8. Please note, it can take up to 10 days for your broadband line to train up to its full speed. So bear in mind that any speed test during this period may not reflect the true long-term speed of your broadband.
9. Please note that the performance tester should not be used to test 500Mb/1000Mb product speeds. Line test results for lines above 330Mb cannot be verified and no further web based diagnostics will be available.

Please confirm that you have carried out the above steps. The speed test may report inaccurate results by failure to comply with the above steps.

[#3]

Thanks for your comments, but it actually hasn't made any substantial difference when I've followed the instructions to the letter. I'll re-run it again in the morning from a fresh start just to be sure.

[#4]

New test done - screenshot attached.

[#5]

You will have to phone Plusnet.

You could also try https://portal.plus.net/apps/kbdfaults

[#6]

I phoned Plusnet and after discussion with a quite helpful chap, they are adamant they will not take it further without the agreement that if an engineer visits and finds no problem, I will be charged around £65 for the privilege. The sickening thing is that because I've changed back to Plusnet from JL and accepted the speed estimate they provided and they are meeting that speed, I'm stuck! Had I stayed with JL and pursued the issue with them, I probably would have more clout because their estimate on joining them was between 11.5 and 18Mb/S. I am considering contacting Ofcom to see what can be done.

[#7]

Have you tried https://www.thinkbroadband.com/download - this allows you to download a selection of very large files, giving you an indication of your true data rate (using a stopwatch!...).

I don't find that BT website gives a very reliable indication.