hi there, i have a worcester heatslave 9.24 bf wall hung combination gas boiler with a wilo smart 25/6 pump. The problem is it sounds like i'm living next to heathrow every time the burners kick in. The pump was new autumn 2007, sentinel x100 inhibiter was put in 8/12/08 as per this site sentinel x200 is on order at TP's, but while i was ordering it a plumber who was in there said that this stuff is not need as boiler dont scale up and that we have the wrong pump on we should have a grundfos 15/60 is he right or does any have any other solutions i would be really grateful as its freezing here Ta Jan