Single shower knob, but water starts and stops during turning?

Hi there,

I am so glad I found this forum. I hope someone here can offer some advice. Please forgive any amateur ignorance I display.

I have a shower at home with a knob whose behavior we can't really make sense of. It's particularly confusing for our 10 year old boy to use. I would love to know if something can be done to fix/readjust the issue, and if it's something I might be able to take care of myself. (or if I should call a professional)

I've attached a picture below, trying to show the problem. Here's the situation:

• 
  If the knob is turned to the extreme left, no water comes out of the faucet.

• 
  If the knob is turned to the extreme right, no water comes out of the faucet.

• 
  If the knob is centered in the middle no water comes out of the faucet.

• 
  If the knob is turned to the left, we get water that tends towards warm/cold.

• 
  If the knob is turned to the right, we get water that tends towards hot/scalding.

As I said, this seems like odd behavior to us, but perhaps you've seen things like this elsewhere. Is this normal? Can you visualize what's going on behind the scenes with the pipes, and how simple it would be to install a more
"normal" and intuitive shower knob?

Thank you for any help or ideas you can offer. Cheers!

Sounds as if the cartridge has gone wonky. Get a replacement cartridge as well as a seat/spring kit.

Matt30 said:

Sounds as if the cartridge has gone wonky. Get a replacement cartridge as well as a seat/spring kit.

Click to expand...

Thanks for the quick response, Matt. I think a google search can pretty much carry me the rest of the way. If I could just ask some follow-up questions:

* Should I try to get a cartridge and seat/spring kit specifically from Delta, or are they pretty standard and available at most hardware stores?

* Is this even something I should tackle myself, or should I call in a professional plumber?

My guess is the stop in the handle is broken.

Has it always been like that? could be that the cartridge was install backwards.
You can get most cartridges at most hardware stores.
Delta has changed their cartridges over time.
Best to remove it. and take it with you or take a picture of it.

Nice photo edit. Helps with understanding your problem.
That valve should be off at 3 o'clock.
As you turn it counter clockwise you should get cold, then warm, then hot.

Thanks, Mr. David. It's been like this since we moved in two months ago. Just getting around to examining it now.

I'll see if I can take the cartridge out and find a replacement at the hardware store.

I appreciate the detailed description and the photos as well. In the next day or so I'll make the trip and see if it solves the problem. Wish me luck!

When replacing Delta parts ALWAYS use Delta brand replacements. There is often a significant difference in performance vs. generic replacements.

A link that may offer some assistance. The third FAQ sounds like the problem you are having. I would opt for a new cartridge instead of cleaning it with vinegar.http://www.deltafaucet.com/customersupport/faq/water+temperature/index.html