Thanks for the all the replies, I have replied to Direnza and I am hoping that my rad was just part of a rogue batch and it can just be exchanged. The Direnza website is currently showing these radiators out of stock. The other problem I could potentially have, is that while they have offered me a full refund, I bought the radiator on Ebay from a 3rd party vendor (the radiator was brand new and hadn't been used, but it's something they are unaware of) and that as a result when they do find out i might not get any refund at all. Waiting to see what reply i get from my latest email.