I just bought a house with a bathroom that has 3 spouts: bath, shower, and hand-held shower. There's a diverter knob (circled in red in image) that's used to control which spout the water goes to.Diverter knob

Well the knob wasn't working very well - I couldn't get the bathtub to work at all - so I played with it a bit. I turned it one way and I turned it the other way and I turned the water on and off. And that process seems to have made it worse. Now the water is stuck coming out of the hand-held shower and turning the knob does nothing.

Actually, as I turn the knob it feels like the knob isn't fully engaging. That same feeling you'd get if it were stripped just enough that you feel the pressure as you turn but then you feel a slight bump as the knob turns around over the nipple it's attached to. Well both the knob and the stem (is the image below called a stem) and nipple (what the stem actually goes into way inside the wall) looked good to my naked eye but to test I took a knob from another shower and tried it here and had the same effect.

So my question is what do I do now? Is it possible this issue is deep inside the wall? I mean I want to redo this bathroom eventually but I'd rather not right now. Is there any way to fix this?

Is this called the stem2?

Does not look stripped?

Here's the diverter behind the wall/tile

  • Do you have access to the other side of the shower wall?
    – HoneyDo
    Commented Jul 24, 2020 at 23:25
  • What you show in the pic is a stem extension.. It operates the diverter. The problem is in the diverter valve itself.
    – HoneyDo
    Commented Jul 24, 2020 at 23:53
  • you might be able to reach in there with a box wrench to disassemble the diverter valve.
    – Jasen
    Commented Jul 25, 2020 at 1:26
  • i do not have access to the other side of the shower wall @HoneyDo Commented Jul 27, 2020 at 2:55

1 Answer 1


Over time calcification builds up on valves affecting their ability to function properly. Sometimes you can repair it by replacing the cartridge or possibly just cleaning it with a de-calcifying agent. Three or four-way valves seem to be more susceptible to this especially if they've been left in one position too long. It's always a good idea to occasionally rotate them through their different functions to keep them operable.
At this point I would replace the cartridge if there is one and if you can remove it. If you can remove it try to clean the inside of the valve body with a de-calc product and a stiff brush to remove any build-up. Be careful of any o-rings that might be there although they should come out with the cartridge.
If this doesn't work you might have to replace the diverter. Hopefully, you can get access through the other side of the shower wall. You wouldn't want to mess up the attractive tile you have. Good luck.

  • thank you this is helpful. i do not know if there is a cartridge, i've posted a picture of the diverter, it does seem like there is something there attached to the pipe, is that a cartridge or does that attach directly to the vertical pipe? it does look like there's something a box wrench could hook onto, do i just turn off the main water, stick in a box wrench, give it some elbow grease and see what happens? Commented Jul 27, 2020 at 2:59
  • I think you have it figured out. First turn off your main. The hexagonal cap in the pic you posted will unscrew from the diverter valve. The diverter cartridge may be difficult to extract because of scale buildup so you might have to work at it. Try a little WD40. With any luck you should be able to find a replacement at your local plumbing store or on-line.
    – HoneyDo
    Commented Jul 27, 2020 at 3:38
  • @statichippo Note that he said "plumbing store", not big-box home improvement store. The counter guy at the plumbing supply store will probably be able to ID your parts with a quick glance and know what part to pick and exactly where to find it. If they don't have it in stock, she'll know what other brand (if any) will work as a replacement).
    – FreeMan
    Commented Jul 27, 2020 at 12:17
  • Also, you'd probably need a socket and extension to get through the hole in the wall and a ratchet on the outside to get that nut turned. I can't imagine any way at all that you'd be able to get a box wrench inside the wall and turn it. I know I'd end up dropping the thing to the bottom of the wall and writing off a tool if I tried...
    – FreeMan
    Commented Jul 27, 2020 at 12:19
  • yea i'm having a hard time finding a wrench that can fit inside that hole and also fit the nut. i have a set of standard plumbing wrench sockets but the largest one i can fit through that hole (1-3/32 and that's only at a certain angle) is a tad too small for the nut. what are my options here? is there a tool i could use that i don't know about? do i need to open up the hole in the tiles a little more? Commented Jul 29, 2020 at 20:55

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