So far RS have delayed, repeated questions they have answers to and, on last contact, said it was over 12 months old (I bought it 18 months ago) and there is nothing they can do.
I responded quoting UK consumer law (and I did buy this with my personal credit card, as an individual, not as a business) that it has to be of reasonable quality, fit for purpose and last a reasonable amount of time. I don't consider a £500 soldering station lasting 18 months a reasonable amount of time and therefore would also be unfit for purpose.
The very least they could have done so far is tell me what Error 12 means. I mean, this is a paperweight and it could be something simple (although i've replaced everything else to guess my way past the error).
Awaiting their next reply.