I am installing a Salamander pump and there is absolutely no way it can be installed by the hot water cylinder - it is going to have to go in the loft - among other things the diagram for this type of installation requires that both hot & cold outlet pipes have air vents ... Does this mean that they just have a high level pipe which is open at the top (like the hot water cylinder) or is there a valve that needs to be fitted to each run? Forgive me if it is a stupid question but I can't understand how if would work without some sort of valve - once you turn the pump on surely water will come out of an open pipe even if it is a lot higher than the junction to the shower itself?