[george renwick]

Cracked di vessel i think went to give it a shake and there was no sloshing in it ,Opened it up and there was no water in it  ,I am hoping this is why its reading 2  as it was only changed a few weeks ago. will it leaking affect the readings ?  Not pressurised properly     
The first vessel is reading 15  before it goes into the new resin ,

[֍Winp®oClean֍]

Unlikely you have cracked it, they are built to withstand pressure, far more than a wfp pump can offer up. Do you have it the right way round?- they are 'directional'. Are all or any internal strainers clear?

[george renwick]

Unlikely you have cracked it, they are built to withstand pressure, far more than a wfp pump can offer up. Do you have it the right way round?- they are 'directional'. Are all or any internal strainers clear?

It must be cracked as there was only resin in it no water . think i dropped it on way back to shed once 

[֍Winp®oClean֍]

But surely if it was cracked you would
either-
1. See the crack
2. See the water coming out of the crack.

I have had a vessel run dry in the past, never really worked out how it happens but it can.