What with the credit crunch and all, Id like to get round to fitting some TRVs in my house. is this a fairly straightforward job - are they pretty much the same size as a standard radiator valve - or is there likely to be some pipe cutting going on? Id have thougt Id have to cut the pipes where below the olives of the old valves wouldnt i - as the pipe will be compressed at that point - in which case id have to move the rad down an inch or so..?