WARNING! in reading the following you need to be a competant electrical engineer and be aware that all power must be isolated before attempting any repair......read on.
I had had the same fault code (F-10) come up on my Indesit WE16. It is related to the pressure switch. However its not necessarily the switch which is faulty. I replaced my pressure switch (Indesit spares online), but on investigation I have found that there was a fault on the main circuit board. Essentially an electrical arc had been shorting across the board on the normally closed contacts which are connected to the pressure switch, hence the code error which gives only the half truth.
So really you need to replace the board, its obivious if this is the problem (i.e. PCB poor design/construction) as you will see a black spot on the board, however you will need to take it all apart, to see said black spot.
I fixed this problem by clearing the remaining element of that track and soldered a new insulated wire between the 2 points.
Hope that helps.
R Webb
January 2007