i would post the pictures to this thread ,
user manual for that boiler here
i'm not a plumber and terryplumb is far more qualified
i would suggest also answering hes questions and doing his suggestion
If you have a small tank in the loft, that will feed the rads. The large black tank in your pic appears to fill the hot water cylinder.
Show us a pic of the valves on rads that don't heat ,as well as those that do. If the rads that heat fully have a thermostatic radiator valve ( TRV) close them and see if cold rads now heat up.
but i would make sure all rads are bleed
its normal in my experience that 1 radiator should not have a thermostatic valve on
and check the pressure - if a filler loop as mentioned, in the other thread is on the system
can you confirm if you have a filling look with a pressure gauge
see section 4
4 SYSTEM PRESSURE
4.1 OPEN VENTED HEATING SYSTEMS
If the boiler is fitted to an open vented system, that is a system with a header tank, the system pressurewill be maintained automatically
4.2 SEALED HEATING SYSTEMS
If this boiler is fitted to a sealed heating system, the system will be pre-pressurised. Your installer willhave fitted a pressure gauge and filling loop so that the system pressure can be monitored andadjusted as necessary.
Your installer will show you how to use the filling loop and advise you of the minimum and maximumpressure indicated on the pressure gauge.
B Check regularly that the pressure is maintained.