View Full Version : low faucet water pressure

Dan Huffman
02-26-2007, 02:33 PM
Hey guys,

Great site! I've got a question that I couldn't seem to find an answer for on here and I was hoping someone could help me out. I tiled a bathroom floor over the weekend, put everything back together, but now the cold water on the sink has really low water pressure.

The floor dropped about a 1/2 inch in height, so I had to re-mount the brace for the pedestal sink on the wall, which required drilling. I don't believe I hit the cold water pipe (I was drilling about 6-8" above the shut-off valve, with the pipe feeding up from the bottom plate), but I can't think of anything else right off the bat. There are no leaks anywhere on the wall or under the floor joists and it's been over 24 hours and they would probably be visible by now.

My thought is that the shut-off valve feeding the cold water is old and maybe the valve won't open up all the way. Either that, or maybe some junk got into the water when I was drilling out for the sink mount?? I'm hoping someone could enlighten me before I spend a million years trying to correct something. Any help is great. Thanks a lot!


02-26-2007, 02:51 PM
Remove the faucet aerator and clean the crud off. Test the pressure first with no aerator to make sure it's okay.

02-26-2007, 03:17 PM
1: Remove and clean off the faucet screen - put a towel on the spout and turn on the water full force to see if can dislodge any junk.
2: Check to see that lowering the sink did not crimp the supply lines
3: Remove the supply line and check the flow from the shutoff valve
(if you have to replace the shutoff valve I would go with the newer 1/4 turn ball-valve - IMO they work great)
4: If you remove the valve check the nipple from the supply to the valve. Sometimes I have seen them pretty badly corroded. I replace them with Brass and not galv pipe.

Good luck

Dan Huffman
02-26-2007, 03:58 PM
I will try the above mentioned suggestions. It's just weird because the hot water side works great, but the cold is so terrible with pressure. I'll give these ideas a whirl. Thanks!

02-26-2007, 05:24 PM
I didn't see that it was only the cold side that had the problem. The aerator would affect both hot and cold pressure, so it's probably the shutoff valve, supply line, or cold stem that is blocked.

02-26-2007, 05:33 PM
If you have old galvanized plumbing, just shutting off and turning back on can give you problems.
It could be blocked at the shutoff,
Sometimes replacing the pipe through the wall and the shutoff helps.

Or it could be a twisted supply tube on the cold going to the faucet.

02-27-2007, 05:28 PM
alot of times when you shut off and old stop the washer stays put. shut off the water pull the stem and see if the washer is still on the stem. happens all the time.