i have a greenstar 30cdi system boiler. Pressure gauge has slipped to less than 0.5 bar and radiators upstairs are only heating up at bottom. Have info about turning white key to lock and then turning white screw to adjust pressure. Only question is, when I do this water starts to trickle out at point where key is inserted. Can someone tell me if this is supposed to happen as worried about continuing just in case it shouldn't.
Thanks
Thanks