ideal classic ff260 boiler on/off?

I have noticed that when the boiler initially switches on with the programmer, it runs constantly for say 30 mins then switches off. It then tends to fire for 2 mins then shuts off for 1 min which it repeats until the thermostat temp in the hallway is achieved which then turns the boiler off. Is this normal? as i feel the boiler is off and on all night until the room stat temp is achieved? The boiler stat is set to 4 out of poss max 6. Any advice would be much appreciated.
It has just had a service and a new fan assy replaced, along with a new vacumm pipe which was split.