Diverter valve (3-valve system) not turning as many revolutions as it used to.

Discussion in 'Shower & bathtub Forum & Blog' started by TamP, Oct 6, 2010.

  1. TamP

    TamP New Member

    Messages:
    15
    Location:
    USA
    I have a bit of an odd situation. I have a Gerber 3-valve shower body. I needed to replace the diverter stem valve, so I picked up a Danco replacement. I pulled out the original, put in the Danco, and discovered that the valve would not turn all the way. Normally, the valve makes several revolutions to go between faucet and showerhead, but now it was only turning a quarter to a half revolution or so.

    So, I pulled out the Danco, obtained a replacement OEM (Gerber) diverter valve, put it in - same deal. Only makes a half turn or so. Puzzled, I put back the original valve (after replacing the stem washer), and now the *original* valve is also only capable of turning a half revolution or so!

    The seat seems fine, there doesn't appear to be any debris in the pipe that I can see or feel. I ended up leaving in the new replacement Gerber valve, and the water does seem to be fully diverting between faucet and showerhead, in that nothing is coming out of the faucet when it's opened all the way. But I'm at a loss as to why it's only capable of turning a half revolution when it used to turn about 2 full revolutions. And why even the original valve is behaving that way!


    Does anyone know what's going on, and how I can get back the original behavior?
  2. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    The parts you used did not perfectly match the old parts.

    It could be as simple as the thickness of the old washer which was compressed, cut into or, missing...

    It could be the dimension of the stem or, seat is different which may be a problem...

    Or it may just be a different pitch in the thread of the stem causing it to run in and out faster...

    Based on what you are saying about the original stem now doing it my guess is the seat.
    Last edited: Oct 6, 2010
  3. TamP

    TamP New Member

    Messages:
    15
    Location:
    USA

    Well, I doubt it's the parts, since the original diverter stem is now doing it. The only thing I added to that was the washer. Any difference in thickness isn't likely to translate to the amount of difference in the number of turns I'm seeing.

    As for your guess that it's the seat - I didn't change the seat. It's still the same original seat that was there previously. And when I tried the original diverter stem, it was at that point being paired with the original seat - so I'm not sure how that would do it. Unless you're suggesting that the seat came partially undone when the original diverter stem was first unscrewed?
  4. asktom

    asktom Member

    Messages:
    515
    Location:
    Victor, MT
    Check that the seat is screwed in all the way. If the washer on the bottom of the stem was in contact with seat when you removed the stem the seat may have backed out some.
  5. TamP

    TamP New Member

    Messages:
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    Location:
    USA
    Now, *that* sounds like a likely possibility. I tried to see if it had slipped, but I realized that they opted for a difficult design. Instead of the gripping faces being part of the opening, they inset it - so my tapered seat wrench can't reach it. Ai!

    I'm not even sure that a stepped wrench can reach it. Do they make straight through seat wrenches? They must. Does anyone know what size Gerber seats require?
  6. TamP

    TamP New Member

    Messages:
    15
    Location:
    USA
    Okay, a further update. I was able to use a regular 5/16" hex wrench to fit the seat. Obviously, I didn't have much leverage, but I used a crescent wrench to help me out.

    Unless it's normally extremely difficult to turn, I'd say the seat's in all the way. I really had my hopes pinned on this one.
  7. Redwood

    Redwood Master Plumber

    Messages:
    7,453
    Location:
    Connecticut
    Is the washer on the stem where it connects to the valve the same thickness as was there originally.

    You have clearly had a dimension change in relation to the stem and the seat.
  8. asktom

    asktom Member

    Messages:
    515
    Location:
    Victor, MT
    When you install the stem assembly, do you have the stem backed out all the way into the gland so the washer can't hit the seat before the assembly is tightened in all the way?
  9. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,253
    Location:
    Cave Creek, Arizona
    If the washer is thicker than the original, it will limit the amount of travel before it "backseats" against the "shower only" seat. If you have adequate flow in either position, do not worry about it. They typically only rotate one revolution or less any way, usually less so that the lever can point up for the shower and down for the tub.
  10. TamP

    TamP New Member

    Messages:
    15
    Location:
    USA
    Yes, I do.
  11. TamP

    TamP New Member

    Messages:
    15
    Location:
    USA
    I just replaced the original Gerber seat with a Danco replacement seat. No real change. I'm honestly at a loss as to what caused this. But as long as I've got full flow, I guess it's not a big deal.

    I'm having another problem as a result of trying to fix this, though. After I pulled out the original Gerber diverter and replaced the seat, I put the diverter back in, and now it's not working properly. I can close the diverter all the way, and the water flows solely out of the spout as it should.

    But when I open the diverter all the way, I'm still getting a good amount of water coming out of the spout. I tried replacing the Gerber diverter with a new replacement from Danco, but I'm having the same problem.


    What's causing this? If the seat wasn't fully sealed, I would expect an issue when the diverter was closed, but there's no problem there. What causes water to still come out of the spout when the diverter is open? (To be clear, there is water coming out of the shower head, just not all of it)


    Edit: Okay, doing what I did with the seat did help the number of revolutions issue. It's just that the Danco diverter sticks in significantly further than the Gerber. So, with the Danco installed, you can't tell there's a difference. But with the Gerber, it's definitely improved. So the big issue remaining is the diverter not shunting all the water to the shower head.
    Last edited: Oct 15, 2010
  12. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,253
    Location:
    Cave Creek, Arizona
    WE would have to see the diverter stem to see why it is happening. The problem is usually with the back seat, NOT the one in the faucet. With a double seated stem, BOTH seals have to occur at the same time when it is installed. Having too thick a "seal ring" where the stem contacts the valve body, can prevent the inside seal from occurring. Try removing that ring and using Teflon tape instead. This may solve your problem, but if it does, also check to be sure the stem is not leaking where it screws into the valve body.
  13. TamP

    TamP New Member

    Messages:
    15
    Location:
    USA

    Just to clarify, aside from the stem washer, there is the cup-shaped washer that the end of the stem backs into when you open the valve all the way. And the other is the bonnet washer which is on the outside of the stem, and seals the entire stem when screwing it into the shower body.

    Are those the two items you're talking about? And does the cup shaped washer actually seal against some surface of the shower body? Or is its sole purpose to seal the end of the stem when the valve is opened all the way?

    Also, the Danco diverter has a deeper threaded section where the bonnet washer is, it's longer by a good bit than the original Gerber diverter. Is there any chance that installing the Danco at an earlier point damaged the shower body in some way?



    Although I've looked around, I've never found a good diagram to show exactly how compression stems work in conjunction with the shower body they're screwed into, so the inner workings are something I have to guess at.
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