F16 on documented European top-load Hotpoint models affects the drum lock position. If it ends up misaligned or stuck, request service and do not force it.
Outer lid and drum flaps
The manufacturer documentation limits this warning to top-load units. The cabinet lid gives access to flaps in the drum; automatic positioning should leave them in an opening zone. They are not the same lock.
With the machine stopped, observe only what is visible through normal access: whether the lid opens, whether the flaps appear, and whether the drum has ended up out of position. Do not put your hand into a narrow gap or try to force a retained drum to turn.
What to report when laundry is left inside
Give the model, exact code, when the fault appeared, and whether the cycle finished or water is still inside. That record lets the technician prepare safe access without assuming the sensor is necessarily the only affected part.
If the appliance is not top-load or the manual assigns F16 to another function, this interpretation does not apply. Consult the Hotpoint index to identify the platform. Do not use repeated cycles to try to position the drum by impacts or inertia.
The priority is to keep the mechanism intact for safe recovery of the laundry.