Generally, they can occur from one of the following causes: 1  Infection. 2  Environmental exposure. 3  Malignancy. 4  Occupational exposure. 5  Collagen vascular disease (an inflammatory condition of the body including the lung) 6  Drugs. 7  Idiopathic (unknown causes)
01-08-2006, 09:34 AM. Check to see if you have the tap marker (handle) turned down to far. The jam nut (lever collar) for holding the marker straight should not be touching the lever bonnet. The bonnet is the nut that holds everything to the faucet. If it is touching, this will cause your sticking Faucet.
There are a number of reasons why pipes knock. One of them is excessive pressure. Anything over 60 psi is enough to cause pipe knock. In addition faucets that have cartridges often cause pipe knock, because they stop the water too fast. When you get water flowing in one direction and you shut it off quickly, all the forward motion is has no place to go. It is absorbed in the piping with banging.