My enclosed shower/tub combo hot water knob just spins & won't turn the water on...I popped the front cover open to tighten the screw only to find that it is stripped (my son had being turning it on/off like this for some time but failed to tell me!) Can I just change out the stripped screw & knob with new ones without turning off the main water supply? I've got the needed materials, I just have no access to the back of the shower 😜 & not sure if I remove the stripped screw & faucet without turning water off first, will it spray a fountain of water into my face or will it be ok ? Thank you for any help or advice. I'm pretty handy with most home repairs, just haven't done too much plumbing by myself & have nobody to ask.

  • Is the screw stripped, or is the stud stripped? If it's the screw, then sure.
    – isherwood
    Commented Jan 20, 2017 at 18:49
  • There are replacement knobs that attach to the shaft of the stem if the flutes are worn off. These have a hardened knife that bites into the usually brass shaft of the stem. You would not have to turn off the water at the outside cutoff to do this. But if you want to change the stem assembly then the water must be off at the cutoff. I know someone who described to me his experience in trying to change a washer on the older type of shower faucet and he claims to have done it with help from another person who does things brute force. They 'got it done' and then dealt with a flood. Why?! Commented Jan 20, 2017 at 21:57
  • Knowing where the main water supply valve is and checking that you can turn it off if you need to is a good start. After turning it off, when you turn it on again do not turn it full-on and leave it: turn it full-on and then back at least half a turn. That reduces the chance of it getting stuck full-on. Next, see if you can find out where the pipes go from the back of the shower - it might be that there are isolating valves somewhere which you can shut of temporarily to do the work. Commented Jul 4, 2017 at 22:10

1 Answer 1


Every shower handle and regulator is a bit different.

See the picture below which is just an example:

enter image description here

If you are really just replacing the handle - which is really items 1-4 (and sometimes 5-6 or sometimes 5-6 don't exist) - then no you do not need to turn off the water. But just by the nature of doing this you are probably going to move the stem and get sprayed with water off and on, or just on if I am doing it.

As every manufacturer is a little different there are various reasons why handles get loose. This example shows a more gears/bushing connection, some manufacturers use a specific shape (square/rectangle/hex) to connect the handle.

The reason why I not this is sometimes 5-6 is stripped and the handle is fine. And sometimes 5-6 is really part of the main regulator and as soon as you start moving them water starts coming out of 8. So if you are sure you are just putting on the handle you do not need to turn off the water. But once you start touching other things turn off the water and turn on the faucet at the lowest point in your house (this will help drain the lines so you don't get a half gallon of kickback in your walls).

As a side note: Turning off the water for your house should be a simple process of turning a valve. You should not be scared to do this and this is good practice as you might need to turn it off in an emergency situation. All adults living at a house should be OK with turning on/off the water and power to house. Also the bathroom or shower could have its own shutoff valve. For a shower this would usually be the floor below and sometimes (not often) under the sink.

  • 1
    In the example you have pictured, if you remove #4 without shutting off the water supply you will definitely have #s 5,6, and 7 blasting out at you accompanied by a large quantity of hot and cold water under pressure. Please edit your answer to state that only #s 1, 2, & 3 can be removed without turning off the water. Commented Jan 22, 2017 at 6:43
  • In the above example, you would remove the handle (item 2 and 1). Then, the faceplate (items 12, 13, or 14). This would allow access to the integral stops (8 and 11). After closing the integral stops, you can continue with removing the cartridge. Not all valves have integral stops.
    – pdd
    Commented Dec 28, 2023 at 22:41

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