LOW PRESSURE?

You don't say if house,bungalow ,flat or in a tower block.

Just a suggestion as I can't see it.

Look for it in the garden you may not have an internal one. dig up in line with the street stop valve feeding your property find the pipe and follow it along toward the house and you should find a garden stop valve. Also it will give you and idea where the pipe enters the house..
Usually termination to internal stopvalves are kitchen under sink, bathroom in or at side of airing cupboard[where mine is]. In halway cupboard under the stairs. If it's a former council property then ask if they have any plans as to where the water feed comes in.

Bob
September 2009