I have a 1.8 silvertop zetec in my Stylus and I am using the standard ford thermostat housing. The housing has a bypass which I know needs to be plumbed into the bottom hose between the rad and water pump, but does the other connection for the heater need to be connected as well or can I just block it off as I do not need a heater. (electric heated screen, for info)

the logical answer is, No you don't need it connected, since if you had a heater, and turned it off, there would be no circulation there.

that was the way my logic was taking me, but I'm sure I had seen somewhere that you should not do this and I can't remember why.

it might be that it gives a 'blead' point, so you can remove air / air locks from the system

Thanks for your thoughts.