Indoor plumbing

I've been working on and off at the plumbing for the solar panels. It's taken a while. Traditionally the plumber turns up but has forgotten his tools. In my case I was permanently short of a crucial and hard-to-find fitting. The local plumbers' merchants don't sell 22mm compression fittings, so these had to be mail order, while the 22mm solder ring elbows that I wanted aren't sold at all in France, and Janey kindly sent me some from England.

This shows the "pump station", which was fairly easy to instal. The pump and other components come pre-assembled, so it was just a matter of getting the pipes to enter and leave at the right places. The green garden hoses are temporary, for pressure-testing the loop. Later I'll be using them to fill it with anti-freeze, but not, of course, before the solar panels go up in the garden....



The balloon-shaped object is an expansion vessel, which enables the liquid in the - sealed - solar circuit to heat up and expand without bursting. It contains a large tough rubber bladder, which I have pre-pressurised to 2.5bar (with a car tyre pump). As the fluid expands, the bladder gets squeezed giving a bit more room for the fluid. There will be another one of these at the other end of the circuit, as I am not entirely sure that 18 litres is enough for the long loop of pipe.

This shows the new piping where it enters the hot-water cylinder. At the top there's a small bronze-coloured cylinder sitting on the pipe: that's an automatic air vent. At the bottom the larger silver cylinder is another type of air collector, designed to get the micro-bubbles out (it says here). I probably don't need both of them, but they make filling the system simpler.



The entry and exit from the cylinder are one inch BSP threaded connections, made with bosswhite and hemp. The bottom one is a special elbow (which had been safely stored in the top of the cylinder by the professional plumber who installed it - it took several weeks before we found it) with a pocket to take a temperature probe.

I tested the system by connecting it up the mains and sealing it off at mains pressure, 2.5 bar. As there were 22 compression joints, 18 soldered joints, and ten metal threaded joints there was plenty of scope for leaks. But to my surprise the only leaks were in the compression fittings: four of them dripped a little. I took these apart and put a little PTFE tape round the olive. This has certainly cured three of them, and I'll check the fourth later though it may need another go.

And we've also made a little progress towards getting the "salle technique" looking more respectable: the local builder came and put a first coat of render on it:



They say they'll be back to put the finishing coat on when the weather improves, perhaps not in the immediate future (it's snowing right now). In the meantime we have their large concrete mixer sitting outside our front door as a promise that they won't forget us.