What could cause sudden loss of water pressure in a brand-new weeks old kitchen sink both hot and cold both normal and spray?

Answer 1

Pipes get mineral build-up, or even rust, on the inside, which often gets loosened when working on Plumbing... even in copper pipe. There is usually a screen or aerator that can be easily unscrewed right where the water comes out. Just take it off, open both hot and cold valves all the way a few times, rinse the screen, and replace it. Sometimes the shut-off valves under the sink can clog with debris for the same reason. Turn off the faucet. Turn off the shut-off valves all the way, clockwise to close. Then take off the hoses (you might need pliers, or better yet, a wrench). Have a bucket (or garbage can, or a yogurt container or something) ready to put the ends of the hoses in. Open the FAUCET all the way on warm to let all the water out of the hoses, and into the bucket. You can then move the bucket and dump it. Next, hold the bucket under the sink so that you can open the shut-off valves one at a time to blow them out. Open them all the way, if possible, but be careful not to overflow the bucket... some valves take a lot of turns. If they are really bad, you can turn off the water main, unscrew the ring that holds on the actual valve stem, and turn the valve handle counter-clockwise until it comes out. You can then pick the pebbles out, or better yet, turn the water main on and off really quickly, while someone else holds the bucket. If you can't turn on the water without making a mess, just scrape around inside where the valve stem goes with a screwdriver or something. Then put the valves back together, and close them. Don't put the hoses back on yet. Go turn the main back on, and blow out the valves into a bucket, first. Otherwise, all that stuff will just clog the faucet.