F16 is documented by Indesit for drum positioning in top-loading washing machines. It can leave the drum flaps out of their access position.
Which part has stopped
The manufacturer documentation describes a problem with the drum lock position system. It distinguishes the outer lid of the appliance and the drum flaps where the laundry is loaded.
With the machine stopped, look only through the normal opening to see whether the flaps are accessible. Do not insert tools through the gap or turn a jammed drum to line them up. A sensor named in the catalog does not confirm that it is the only cause of the fault.
Preparing the support request
Note whether it happened at the end of the cycle, whether water is left inside, and whether the outer lid opens. A photo of the panel and the full model help confirm that F16 is being read on the correct platform.
Support refers this issue to service. Do not keep restarting the appliance so movement can bring the drum into position. If the appliance is not a top-loader, consult the Indesit index and its manual before assigning this meaning to the code.
Retrieving the laundry does not require forcing a mechanism whose lock is still engaged.