F1 means that there is water in the base pan below the bottom drawer. This usually happens because something was stacked too high in one of the drawers when it was running and this caused the lid to not seal up when the drawer was shut.
You could also have faulty lid actuators that won’t pull the lid down all the way to seal up to the drawer, or possibly a leak from a faulty inlet valve that is leaking. To correct the issue, pull the bottom drawer out. There are 2 square plastic push tabs on the right and left side of the drawer just behind the front panel.
Pull the drawer forward and push in on these tabs. This will allow you to pull the drawer out a bit further so that you can get towels in the base pan behind the drawer. Soak up all the water and leave the unit unplugged for 24 hours to let it dry out. Once it’s dry, the F1 error shouldn’t return.
If the F1 error doesn’t go away, then unfortunately you will need to replace the small filter board in the back left corner of the base pan under the plastic housing because that is what senses the water.