v loud saunier duval therma classic f24e?

Just moved into my rented house on friday, went to turn on the boiler and saw the pressure was low so I turned the blue valve to raise the pressure and the bottom part of the valve came off. Put the valve back into place but now the noiler is leaking water and making a very loud banging noise that can be heard all through the house. We have a tenants emergancy number so I phoned that and the guy on the other end told me to switch the boiler off completley and the banging noise should stop and eventually the water will stop leaking......it hasn't it is now 2.30 in the morning can't sleep because of the horrible banging noise. I feel really bad for the neighbours becuase it must be keeping them awake and I'm angry that the guy who I phoned on the emergancy number didn't help striaght away becuase it was an emergancy!!!!!!!!!!!!!!