Here's what I know. Our kitchen sink used to work fine, then one day the water flow was suddenly really low, like just slightly better than a trickle. We called our landlord about it, and so he came by one day while I was at work and fixed it. My wife says he basically went under the sink, did something, and the problem was resolved in a matter of minutes.

Unfortunately the problem has come back. Knowing that it's supposedly very easy to fix, I'm trying to figure out how to do it myself; but I've looked under the sink and the only thing I can really imagine he did was something involving these knobs:

Knobs under kitchen sink

However, for the life of me I can't seem to turn either knob in either direction. I've tried loosening the screws, but those just seem to hold the knobs on (as I'd expect, but you can never be too sure).

Obviously I don't know much anything about how sinks work, or else I wouldn't be posting here. I'm hoping somebody knows exactly what's wrong and can tell me what obvious thing I'm missing.

If it's just that the knobs need to be turned... any idea why they'd be basically impossible to turn? Does something else need to be adjusted first?

1 Answer 1


First confirm that the problem is at the valves and not a clogged faucet screen.

Backing-up the valve with an adjustable wrench you could turn your knobs with channel locks but be prepared for a few drips, or something completely catastrophic to happen. Not something to be messing with on a Saturday evening. Being frank, those valves are crap. Preferably use 1/4 turn valves. Seeing that these are compression fitting, they're easily changed. Ask for these.

The choke point is at the valve, this clears the blockage: Once you have the valves spinning freely, shut them off and disconnect the leads at the faucet (back this up carefully, do not twist the copper leads). Run the lines into a bucket, completely opening and closing the valves several times. Reattach them, turn them on. Do not touch them again without repeating these steps. Remove the faucet screen and run some water for a bit. Reinsert a cleaned screen, done.

  • So the idea is to loosen them slightly? That would increase the water flow? What's the catastrophic thing: that I might break the valve and water will come pouring out?
    – Dan Tao
    Sep 28, 2014 at 18:28
  • You might loosen the whole valve from the supply pipe if you don't back it up and it spins the compression fitting back there. Just trying to warn you of the plumbers' nightmare. (anything can happen) Back up the valve as close as possible to the knob to avoid accidentally dissembling the valve. The idea is to close and reopen them, crushing the blockage and then freeing it. Remove the screen from you faucet while you purge. Best practice is to remove the lines at the faucet and run water into a bucket to purge the lines after messing with anything. @DanTao
    – Mazura
    Sep 28, 2014 at 18:37
  • All this may be unnecessary if you find a clogged faucet screen.
    – Mazura
    Sep 28, 2014 at 18:39
  • And yes, you might break it (plastic stem). But so would the next guy who had to turn it off.
    – Mazura
    Sep 28, 2014 at 18:44

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