Quote "now there is no heating at all upstairs"
Bleeding radiators would not do that, It would if pressure dropped too much Stop any heating, NOT just upstairs. DO you have a pressure gauge, should read about 1 bar, for a combi boiler.
BUT
As you do not say what you have, just F30, difficult. I will assume ferroli f30, So you will have a filling loop somewhere close to the boiler, usually a flexible metal braided pipe, with a valve on. open the valve so pressure reads 1 bar, WHEN COLD.
Next time give full details, OR you might not get an answer
SD
December 2012