Gradual re-fit of radiators

[svouts]

I have a compi boiler and I have removed the radiators for decorating my flat. Can I install only some of the radiators as I finish decorating each room and turn the heating on or I need to install all of them before turning on the boiler?

 

[denso13]

You can use the heating before all radiators are fitted. Will mean topping up the pressure each time. I would also add some inhibitor once you are done, which you could put in the last radiator while refitting.

 

[svouts]

Thanks!
What does it mean “topping up the pressure”, do I need to do anything or the system will adjust the pressure when I start the boiler?