This is from our MEL for the A343 and I think the A345 is the same.
28-27-02 Aft Transfer Valve
Fuel jettison from centre tank is still operative.
The CG control is no longer available.
The fuel consumption is increased by 1.5%.
Our software has an ECAM warning for this fault. The FCOM states that the fuel burn increases by roughly 1%, so I guess the MEL covers the worst case scenario. (dispatch reasoning) It does not recommend resetting the FCMC with this ECAM. It is a long procedure but essentially it says to manually XFR the fuel forward. It then goes on to state that if the man xfr doesn't work, then do the same procedure but only above 270kts and not in climb. (gravity does the work then)