New extension - can boiler handle 2 more radiators?

[philv]

Hi,
i am thinking of having an extension built.
I would like to keep the existing bouiler and
just add a couple of radiators.

The specification for th boiler says -

1) Expansion vessel capicity = 6 liters.

2) Maximum heating system water content using
fitted expansion vessel = 60 liters.

Now if a radiator has typically 6 liters of water inside (100 cm x 60 cm radiator) -

does that mena i can have approximately
10 radiators (100 cm x 60 cm)?
ie 60 liters (total capacity) / 6 liters (each radiaot).

Or would it be 9 radiators because of the expansion vessel?
ie 54 liters (total capacity - expansion vessel) / 6 liters (each radiaot).

Do i have to think about the pipes aswell?

Any help much appreciated.
Thanks,
Phil.

[marcjml]

It's not how much water the system can hold but more can the boiler kw output cope with heating it. Burner pressure can be adjusted within manufacture instructions.

[marcjml]

It's not how much water the system can hold but more can the boiler kw output cope with heating it. Burner pressure can be adjusted within manufacture instructions.