If the system has been switched off so the house and HW cylinder have cooled right down, those times might not be too bad, but could be your rads are undersized. The pump stopping and starting seems odd. What controls in the way of thermostats and auto valves do you have? When any stat is calling the pump should run continuously (as Harry said), though the boiler might stop/start firing on its control-stat.is that from cold ? I don't use the system when I'm staying away from home, everything is switched off. but when u fire lt up , it takes time , you can hear tge pump going for 1 min then it will stop for a min,
I did read on this forum u think , they usually do this when the hot water isn't clearing away quick .
rads are from 1984 .when bleeding the water Is clear .