Hello Michael. Apologies for not getting back to you yesterday.
After sending this request, I later discovered that Bosch themselves would pickup the pressure FOC and examine it. If there's a problem (as I believe there is with the pressure outlet, as did the assistant I spoke to), they'll alert me as to how much it will cost to rectify, and if not, there will be no charge.
In light of this, would it be possible to request my £16 back?