I have a 3 Handle Shower/Tub where the left is Hot, middle is shower, and right is cold. The Hot knob works exactly as expected, the shower knob turns the shower on and off, BUT the cold knob will turn on cold water, and also turns the shower on!
What must I do to repair this issue? — Seat or Stem issue? I feel confident it's just the diverter the middle knob but am not 100% certain.
This is an image of what my set-up looks like
(note this is a stock google image not my exact set-up)
EDIT
I thought I could remove the knob but I am having issues….
I removed the screw from the knob itself like this image
But I am unable to twist off the knob itself. If I twist the ring behind it that is against the wall, that will loosen up until it is flush against the knob but then it will not move any further like this image.
EDIT 2
After a few mighty taps with a hammer this way and that way I got the knob off and used my valve stem socket set to get the valve stem out. Now, I have the replacement, but floating around in the packaging was an extra O-Ring washer and a "bolt" that was not attached to the valve stem.
Where do I attach these two parts? Here is an image
EDIT 3
Last Question and I'm all set! The "pieces" were caulked into the wall, most of the work was spent removing the caulk so that I could actually remove the valve stem. As you scan see in the image below, I removed the caulking from the diverter but it remains on the hot/cold. Is this a necessary evil? Or will it be okay if I do not re-caulk the diverter?
Best Answer
I would say that the white seal looks like it fits to the flat sealing surface at the coarse threads. The coarse threads pull the flat sealing surface onto the valve body and the white "washer" makes the seal. If this is how it works you will not need any Teflon tape or pipe dope on those threads.
I suppose the brass ring is a "valve seat" that goes into the valve body, but it has been a long time since I messed with one of these diverters and I don't know the details. Look into the hole with a light and see if there is a replaceable seat inside. Examine the edge of the seat to see if there are grooves. If you don't have a seat wrench. perhaps you should leave the existing one in place and see if the diverter works with the old one.