Brand new machine won't run after 5 minutes

We bought a new machine for our little gite in France to rent out. It has never been used and only now are we renting the gite, so started the new machine to check it out. The eco light/soak light flashes and it says that the filter is blocked, but as it is brand new - of course it isn't! Filled salt to required level and that light flashes also. We have tried filling it manually with a little water and checked all inlets and outlets and even took the bottom panel off to check coneections, all fine and obviously brand new. As we didnt try it last year, it is out of warranty!!! Can anyone help - the filter is clean and all connnections are fine!