Ive got a Malaga 2 water system which ive not used for a while. When i fire up the system no water seems to be drawn out of the taps etc. There is a lot of hissing from the taps when i turn them which then dies away to nothing. When I turn the taps off, the system then 'glugs' as it starts to fill with water again. After a few seconds or even if i leave it for 30 mins I turn the tap on again and air fires out and then dies away again (no water). I would automatically suspect that there is an air lock somewhere but ive drained the main tank and the Malaga system and re-filled it again. Please help becuase I need this working by Tues!!!