Thanks Jason.
I've attached a screen shot showing a couple of screens from the Server Behaviour Configuration. What do I need to change exactly? In the right hand image, I found the Keyword filter OK - changing type from Edit to Keyword?
But I wasn't sure about the separator - I tried changing the OR in the OR box to a comma, but that started returning all schools regardless of what I entered.
I'm sure this is simple, but if you could look at the screenshot and let k=me know exactly what needs to go where that would be great.