I had a new bathroom faucet installed yesterday by a professional plumber. I did not notice it at first, but the unit WHISTLES when the faucet is turned on. Also, the water pressure does not seem as good as my older faucet.
He turned off the water from the SHUT OFF VALVES under the sink to do this job.
The faucet is washerless.
Please advise anything you can on this. He will come back, hopefully at no cost.