[thomastee]

Many thanks for the reply L.J.
So if I connect the banjo downstream of the gauge and downstream of the shut off valve, why would my system pressure reading be any different? Do you mean that the banjo should be after the gauge T but before the shut off valve? If so, I don't quite get why my pressure would be different then compared with leaving the banjo connected at the FD. (Sorry if I'm being dumb!)
Also, is the pressure relief valve the little spring-loaded one to the side of the FD? If this isn't functioning properly, does that mean I have to take the FD off to replace or is there a less heartbreaking solution?
Thanks again,
Thomas