If you do that you will be breaching manufacturers instructions and liable to damage the pump as you will prevent expansion. It is OK to fit NRV's to the outlet side of the pump - but not the inlet.
Please be careful about the advice you give on here as that directly contradicts express instructions from Salamander.
Indeed, this is something that I've since learnt, bearing in mind this topic is over 13 months old. That said, although I would suggest the manufacturer's instructions are obeyed, I still don't understand exactly what expansion Salamander are worrying about. After all, it's perfectly acceptable to have a NRV on, say, an outside tap - so what happens to the water in the pipework as it heats up and expands during the summer months? I wonder if the recommendations are more to do with restriction to the water inlet and the prevention of cavitation rather than buildup of pressure.
