The engineer called. He was exactly on time, he was polite, and he removed his shoes as he entered. The tap that had been causing the occasional leak had been dormant for a few days, but exactly on cue it started to leak copiously this morning. As the tap was moderately expensive and still under the 5 year warranty, the Gorse Fox had called the manufacturer. Hence the arrival of the engineer.
He took one look at the problem and explained that it the o-rings, not the valve. It it had been the valve, the tap would drip; but as it's the o-rings the barrel leaks. It didn't take him long to rectify the situation and his diagnosis was that the water pipes hadn't been flushed through properly when the house was built and small bits of grit had got in to the mechanism. Seemed plausible, particularly when he dug out just such a piece of grit. All sorted now - just in time to have the worktops fitted tomorrow.
Most of the rest of the day has been spent writing code. There are a few things that the Gorse Fox wanted to tidy up in the blog and it is easier to write a program than to go through each relevant entry and make manual changes.