Thursday 20 October 2005 4.11pm
Sounds like either water hammer or an airlock.
First check that your stopcock tap is fully turned on. And when you have checked that, you should turn it back one quarter of a turn so that it doesn't jam. That may help to reduce water hammer. If it is water hammer and it persists, has one of your pipes become detached from a mounting?
If an airlock, try this: http://www.fingalcoco.ie/YourLocalCouncil/Services/WaterServices/AdviceandUsefulInformation/GettingRidofAirLocks/