Bump.
Bumpy around here, innit?
The problem won't be the Shurflo - £ to a penny it's the 'digital' varistream playing up.
Check out the blue dial inside and turn it this way and that in an experiment to find out why the hell it's ruining your life. Well, it seems like it, doesn't it? You don't need this kind of carp.
Check the varistream first.