I decided to try to have another go at getting hold of the user manual for my central heating boiler, I gave up before after hitting the following roadblock.
The manufacturer does not have it online, though there are a few places that do, they charge for it. In one case £9.90 for the PDF (all 18 pages of it) and another £25 for access to their website. This is all not having a clue what you're really "buying", which is also a document that they don't have copyright for.
There was me thinking that making commercial gain out of copyright infringement was illegal?
In the end I found the manual on the website of Aire Valley Homes Leeds who have the decency not to try to scam their tenants for a simple manual download.
Here's the manual (a PDF document of course) Chaffoteaux Britony 80 SE and 100 SE installation and operating instructions.