Hi there quick bit of advice please, I have an Ideal (mini) combi boiler, last night I bled 2 of the rads and haven't had any hot water or heating since. The pressure gauge is at zero bar, is this because I have reduced the pressure in the system? If so, what is the process for briniging the pressure back up (am I right in thinking it should be at about 0.7 bar?). There are 2 taps under the boiler, one blue on right, and one yellow on left. Can only get about 1/4 to 1/2 turn on each one, but nothing happens anyway. Am I barking up the wrong tree or am I a waste of space who needs a plumber? Please help!!

ps. advice on this will be happily exchanged for plastering advice! Thanks in advance.

pps. the boiler makes the usual noises when hot tap is turned on, ie, fan turns and there is a click for ignition but nothing happens.
GC no.  UH158324
model no. mini c28