Normal filling pressure - combi boiler hot or cold?

Should be a quick one:

CH needs topping up. Not really paid much attention to the pressure guage in a while - just noticed it's hovering just off '0 bar' when cold .

I know what needs doing with the filling loop (tho never needed to do it before). The manual says to fill to 'Normal Filling Pressure of 1bar'.

Is this when boiler is on (running CH for a while) or off (stone cold)?


Dumb question, but they're easier to answer than dumb mistakes.

Thanks for your time and help.

WC

cold

Bugger me, that was swift!!

many thanks, TWGAS.

WC