I have a one-handle "Marielle" model Pfister kitchen faucet diagrammed here. It leaked, so I replaced the cartridge, which solved the problem. A few weeks later, I happened to drain my hot water heater to get rid of sediment. Right after that, perhaps only coincidentally, my kitchen faucet output was reduced to a dribble, both hot and cold equally, even with the spout's aerator removed. Oddly, the hand spray still has plenty of pressure (hot and cold). All other faucets work fine. Disassembling the faucet, including taking apart the cartridge, which is clean, reveals nothing. The diverter valve (951-050 in the diagram) had a tiny chunk of sediment but removing that made no difference. Running wires through the faucet's connection legs finds no clogs or gunk. Disconnecting the incoming hot and cold lines and diverting them into a bucket reveals they have plenty of pressure. The pressure is dying after entering the faucet.

What's the cause of my problem? The cartridge? Diverter valve? Something else?


2 Answers 2


A new diverter valve fixed the problem. Pfister also sent the two big o-rings (950-910) which undoubtedly helped too, since the bottom ring seemed a bit loose. Bottom line: if your hand spray has good pressure but your faucet doesn't, it's the diverter valve.


Whenever you have sediment going through your water system the end result is the sediment usually getting stuck in a filter. Your sink has a filter on the nozzle. You need to simply unscrew the very end of the nozzle (941-004) and clean (941-005). This is the culprit 98% of the time.

In the future if you are cleaning any plumbing and possible sediment is running through your house turn on the washer supply hose (a lot of times these are dual headed and if it isn't unscrew the hose to your washer) for 10 mins or a good couple buckets. You might not see much but that will keep you from cleaning a bunch of faucets. And tub is OK to use but your valve (if newer) probably has filters in its cartridge.

  • 2
    It's not the filter/aerator. As stated in the original post, there's no pressure even with the aerator removed. Except for one small piece in the diverter, sediment wasn't found anywhere.
    – Les Paul
    Jul 2, 2013 at 0:17
  • 1
    Pfister says the problem is the diverter. They're sending another under warranty.
    – Les Paul
    Jul 2, 2013 at 0:30

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