This is the same boiler as yours but 31 kw output and has hot water components. Bathroom tall radiator is forever getting air in it.
Been in this house for 38 years, this boiler in no 3. Bathroom radiator has always entrained air be it open vented system or sealed like last two boilers
I also get ticking of pipes as these heat up and cool down especially with the type of controls I am using. Bedroom rad and bathroom switch at 6.30 am. It is like an alarm clock