worcester bosch 240 combi boiler/circulation pump?

we have a worcester bosch 240 combi this has been shut off and drained down for a while,we filled it to 1.5 bar bled all rads turned gas on and everything seemed to work ok.but as it is summer we shut off the central heating and had hot water only on, everything seemed to work ok but then I noticed the circulation pump was running when hot water only was being used surley this should not happen?