In reply to a post by b4dger:

I seem to have had most faults over the years with my delicate overhead line which passes through a lot of trees

Like you I'm also with Freeola. Just make sure the fault is the same when directly plugged into the TEST socket which will show if the problem is on BT's 'side' and if you have a spare router give that a try as well just to make sure!

Freeola/Entanet were able to run tests for me in the past which showed a damaged line causing a HR fault. I'm not aware if they call this CIDT or not though. One of the tests they ran was with everything unplugged at my end which still showed as a fault when they ran the test.

I've tried 3 different routers (currently on a speedtouch 585), 4 different microfilters and even new modem cables. So I'm pretty sure the fault isn't at my end.
If Freeola did a test with the modem/router unplugged it wasn't a CIDT test.
A CIDT test needs the modem/router to be connected to the line and switched on.

In reply to a post by terrencemorgan:

A CIDT test needs the modem/router to be connected to the line and switched on.

All I know is the test found a problem on the line (very small cut in the cable insulation) and BT replaced the line and all was well...
Tests were performed with the router connected as well.

My advice would be to focus on getting your ADSL connection fixed rather than 'CIDT' !