The swimming pool shower always takes a while before the hot water comes; it's usually about 45 seconds before the water starts to run warm. But a couple of months ago, I turned it on to rinse it off, and I noticed that the hot water arrived sooner than normal. Odd, I thought, but perhaps someone had run some hot water nearby, and that had speeded things up. Or something.
On a separate occasion, I was in the pool area, and heard a strange noise, like water hissing. I eventually traced it to the shower mixer valve. Gosh, I thought, with my ear to the valve, I can hear the pumps circulating the water around the system.
It wasn't until I felt the shower wall, and noticed that it was warm, hot even, that I came to the conclusion that perhaps my subconscious had been avoiding. I have a leak of hot water in the shower. Now the shower is built onto the wall, and the plumbing is behind the tiles, and mortared in. Just where you don't want a leak. Anyway I called the plumber in.
In principle, as long as the leak is in the shower joint itself, or thereabouts, there's not a big problem. But if the leak is hidden in the bowels of the building, and the hot water is comimg at you via the plastic conduit through which the pipe is threaded, you have a big problem. The worst case scenario is a need to re-plumb the shower with new pipes threaded through the building, plus perhaps the need to cut off all the hot water to half the client accommodation, while that's happening.
Of course the tiles need to be removed in order to get at the pipes, and they can't be removed without breaking them. And of course we have no spares, and of course they're no longer manufactured. So we spent a good half-day in Le Mans trying to find a good match. It's amazing how many different shades of white there are, but eventually we found some that can be cut to size, and that match reasonably well.
The plumber dug into the wall and got to the hot pipe without damaging it, and fortunately the leak was in the joint to the shower fitting. The culprit was a nut that had split, possibly under the pressure of having too much hemp fibre in the thread. I remember that hemp fibre was what my grandfather used for sealing plumbing joints; well, they still use it in France. It expands to seal the joint, and perhaps this hemp had expanded too much and split the nut.
It's easy enough to see in the last picture; the nut nearest the shower connector has a dark line across its width. It has one the other side too, and they're both cracks that spray water everywhere, when under pressure.
I glued the replacement tile in on Tuesday, yesterday I grouted it, and today I connected up the shower fitting. Fingers crossed, but it seems OK.