This is probably not a new topic but I can't find exactly what I want elsewhere on the site. I've drained the cold water tank to fit a new bath tap and when I've turned the water back on i get a vibration from the pipes, it stops when i run a cold tap in the downstairs loo or flush a toilet. I've now drained the cold tank several times and then filled it up again but the vibration still comes back, sometimes in the same place sometimes in different places around the house. I'm assuming its some sort of airlock. My Mrs want to call in a plumber but I'm not wanting to fork out £X00 for something that may be simple to fix. Help me please!