Central Heating Help

[AP2000]

We moved into a 7 year old house at the start of September that has aa Powermax 155 Boiler and only recently turned the central heating on.

The radiators seem to work ramdomly, for example some work one day and not the other and vice versa. Some raditors get hot at the top and stay cold at the bottom. Also, the CH and HW is set from 7-9 (morning and evening) and I find that the radiators get cold by about 8.

Any idea what could be wrong? The pressure meter on the boiler read abt 1.2 when cold and 1.8 when in use.

I am not sure when the boiler was last serviced.

Thanks in advance.

 

[AP2000]

Can anyone help me with this?

 

[2face]

sounds like air and maybe a rad balence is needed here. do they have trv`s on the rads ?? this maybe why the rads are cold ie: the rooms are up to temp ..
a little more info please .