Dont know about F7 but I've just cleared an F8 fault. There is next to no useful source error codes for F&P on the web but what I cleared it by cleaning all the filters then holding the reset (start) button for a good 3 to 5 seconds. I think the important part is that you have to hold the reset button for that long before it works. Just pushing it doesnt help.
Grantm
February 2007