kitchen faucet clunks continually while on
We have a fairly new single-handle kitchen faucet with a separate pull-out sprayer. I don't know the brand. Yesterday it suddenly began making a loud, continual clunking sound whenever the water is running, and the water comes out of the faucet with a kind of "stutter." When we use the sprayer, there's no clunking and the water comes out in a normal stream. I read a few posts on this site about faucets clunking once or twice when they are first turned on, but ours keeps clunking from the time you turn the water on until you turn it off.
What causes it and how can I fix it?