At 14:20, my main comms line went down. And stayed down. 40 minutes later, I noticed and reported it to Daisy.
Nothing happened for a long time. I kept phoning Daisy to give them a prod, and eventually, at 11pm, (11 hours later) a van from Openreach was parked nearby, checking the green cabinet that my line goes through.
That didn't help, and I called Daisy again.
Openreach sent another engineer. He came here at 3am. He phoned, I woke up, and let him in. So he started measuring voltages - he thought they were OK. Then he revealed that he wasn't the engineer for private circuits (which is what I have), didn't really know much about them and needed to call a colleague to talk him through what to do. He left without fixing the problem, and said that I needed another site visit from another engineer.
At 5am, the third engineer arrived. He first went to the exchange and swapped out a card, but that didn't help. Then he phoned, woke me up, and I let him in. He was confident that swapping out the BT equipment here would fix it - it didn't.So them he started measuring voltages, but he had an analog voltmeter, and it was clear to me that it wasn't accurate enough, so I offered him my digital voltmeter, and that revealed the problem. I was getting 116 volts on one line (it should be 120), but only 111 volts on the other, and 111 volts just wasn't quite enough.
We were losing five volts somewhere. Progess! So he went back to the exchange - maybe a fuse has eroded and that where the five volts is going? No, it wasn't.
At 10am, the fourth engineer arrived. He went up his ladder to the telephone pole outside my house, and saw the problem immediately. The screw terminal connection was corroded. So he snipped off the corroded copper, connected it with a compression-fit connector, and immediately my comms was working.
So I had an outage for 21 hours, because whoever fitted the line originally, thought that a screw terminal connection would be good enough.
I'm making an SLA claim for this.