So. This water filter business. You have to filter out the chlorine (and all the rest of it, but chlorine is the main thing, and bottled water is a ridiculously expensive and resource-wasting way of doing it, and jug filters are expensive and can get infected, so a filter for the drinking water tap is the one). I chose a simple mains filter thing where you have to change the filter twice a year (cost 30GBP each time).
It came with instructions and I fitted it as per. There was a line tap which clamped on the copper mains water tube, then you screwed something in so that it pierced the copper tube and the water went off down through the filter, et Robert est votre oncle, as the French would say. And so to bed.
About 3 o'clock in the morning I woke up and thought "I know, I will just go down to the kitchen."
When I got into the kitchen, there was a hissing sound coming from under the sink where I had fitted the line piercing junction thing. A jet of spray was firing up out of the junction. It had only just begun as I walked in, because there were no pools of water on the kitchen floor at all. So I turned the water off at the mains, went back to bed and sleep and the next day asked the Man to come in and do a proper job.
Quite a coincidence eh? Not often I wake at 3 a.m. (not then anyway - happens all the time now, since the Great Clearout), and even if I do wake, the words "I will just go down to the kitchen" are not often the first on my mind.
It must have been that the leakage began in a very tiny way, and made a noise in the pipes, and the sound of the very tiny leakage must have been conducted back through the central heating to the radiator by my sleeping head, and it was that that to woke me up. That must have been it.
Or a complete coincidence, of course.
The thing about the coincidence explanation is that it is unfalsifiable, and therefore unscientific.