Thanks everyone, this is really helpful information! I'm going to do the pressure test as per Tony's instructions in a little while, then try the adjustments. two questions though:
1. If you need to raise the cold pressure to get it up to spec, does that mean you have to bring the small pin up, rather than tap it down? And if so do you have take the WUR apart, or is there a simpler method?
2. Does the adjustment you make to the 'cold side' have an impact on the warm pressure adjustment? Looks like it would, just from looking at diagrams. If that's the case does it make sense to do the cold adjustment first? Pls correct me if I'm wrong. the diagram I'm thinking of is this one:
