Crip Moorey

Hey John, welcome to the forum.
I live in Japan and have 2 elder trees which both produce heaps of flowers and berries every summer. The flowers smell the same as I remember from my childhood in the UK but the berries taste really awful. I've successfully made elderflower 'champagne' and cordial but the raw taste of the berries has put me off trying to make anything out of them.
I have no idea what variety of Sambucus it is but do the berries always taste that bad unprocessed?
Will be looking out for your book if I don't win a copy here!

Harvest when the sap is down, november through feb here in japan, dry for a year until evenly tan coloured, discard any with discoloring as that'll be rot setting in.
Three year old growth is best as mentioned above.
I'd also recommend splitting it and using it as laths under an earthen plaster rather than the cordwood idea.
Take a look at this blog for inspiration:
http://holzhueter.blogspot.com/p/blog-page_27.html?m=1

might not the water in the heatexchange coil become hot enough to boil and therefore run the risk of a 'boom' if all the faucets were shut?

I'm in Japan and not that far from you.
website here.