you may have a blockage if the low pressure problem is a recent development, but if you have never had good pressure it may be that the header tank is not high enough above the cylinder to create a good pressure.
p.s. main place i would guess at for a blockage would be the pipe which goes in to the bottom of the cylinder from the tank, if the tank has lots of limescale in it it could get blocked up at the bottom.
James, April 2009
