worcester bosch combi?

i have a worcester bosch greenstar combi boiler, when i turn the hot taps on it takes ages to heat the hot water (5 mins) the problem is that whenever i run the hot water the radiators seem to get warm first, this is even with the thermostat down low. It seems as though it heats the rads before the hot water taps. Anyone got an idea why?

neillush
October 2009