They are there in a manner of speaking, a post by me on page #3 of the known error codes, linked to a post by Dave Conway on page #2 Indesit WIDL codes. They are the same. Rather unhelpfully F03 is listed simply as NTC fault. Turning the water off should have no effect on the machine other than stopping it with H2O in display.
I think one method of reset is to press and hold the Start/Cancel button for a few seconds until you get three beeps, then press and hold Start/Cancel & On/Off at the same time until you get three beeps. Usually works for me.