I am replacing my faulty toilet filler valve with a new Torbeck one. It's a very easy job, except I have one query - the instructions say the correct water pressure must be maintained using a restrictor if necessary. It then says if the pressure is below 1 bar there should be no restrictor, but I should fit one if the pressure is over 1 bar. My problem is that I have no idea what the pressure is. My toilet tank is on the first floor and is gravity filled from the loft tank. Can anyone suggest whether the water pressure for my set up (which must be fairly standard) is above or below 1 bar?