I just had the error F on my machine (but not the water pump problem). I phoned the Hotpoint Service Centre and they hadn't heard of error F. I was all set to purchase a new one when I thought I'd try the machine one more time. After a minute or so it started up and finished a complete cycle. Once complete, the error F had gone to be replaced with the normal 85. Maybe I was just lucky!
Darren, January 2007