Quck answer
If your shower valve stems are stripped, there are several steps you can take to fix the issue. First, turn off the water supply to the shower. Next, remove the handle and the trim plate to access the valve stem. Use a wrench to unscrew the valve stem and remove it from the shower. If the threads on the stem are stripped, you can try using a thread repair kit to fix them. Alternatively, you may need to replace the entire valve stem. Once the stem is fixed or replaced, reassemble the shower and turn on the water supply to test for any leaks.
If you have an older shower valve, you may have encountered the problem of a stripped shower valve. When you turn the handle to adjust the temperature or flow rate, nothing happens. This occurs because the ribbed end of the shower valve stem has become stripped and the handle can no longer grip it. This is a common issue with older valves and may or may not be fixable. If it cannot be fixed, you will likely need to replace the cartridge or compression valve, depending on the type of faucet you have.
Before resorting to that, there are a couple of quick fixes you can try. Alternatively, there is a shower handle stem repair strategy that may be effective, although it is not as quick. Any of these repairs can buy you some time if successful, but when the shower valve stem is too stripped to grip the handle, it is usually time to replace it.
Two Quick Solutions for a Shower Handle Stem
If you have hard water, mineral deposits or scale can get lodged in the ribs of the valve stem, turning a ribbed cylinder into a smooth one. Vinegar can dissolve scale, but it requires time to work. If you can remove the valve, you can soak it overnight in distilled vinegar to resolve the issue. However, removing the stem may not be an option. In that case, create a paste using borax and vinegar, and apply it around the exposed stem after removing the handle. Keep it moist for several hours by spraying vinegar on it. When you rinse it off, the scale should be gone.
The stem may be worn, but if you can still see ribs, you can potentially get the handle working by wrapping plumbing tape around the faucet stem. Wrap the tape multiple times until the handle fits tightly. You will likely need at least five turns. You may encounter some difficulty putting the handle back on, which is a good sign. Once it is back on, tighten the screw as much as possible and give it a try. If it works, great! You probably won’t need to do anything else for at least a year.
A Lengthier Solution
You may be able to deepen the grooves on the stem. The quickest and most effective way to do this is by using a rotary tool with a thin grinding wheel attachment. You do not need to deepen all the grooves, but you should work on at least four, evenly spaced on the stem. If you do not have a rotary tool, you can use a file instead, although it will take longer and require more effort. After completing this basic shower knob repair, it is a good idea to replace the handle. If the ribs on the stem are worn, it is likely that the ones on the handle are also worn.
Replacing the Cartridge or Compression Valve
The most effective way to fix the shower handle is to replace the valve. Before doing so, make sure to turn off the water supply to the bathroom. Start by removing the handle. In case you have a cartridge valve, you can remove the cartridge by either loosening the retaining ring using locking pliers or pulling out the retaining pin with needle-nose pliers. Removing the cartridge might require some effort. If you find it difficult, you can consider renting a cartridge puller from a local plumbing supply store. Take the cartridge to the plumbing supply dealer to get a replacement or order one online.
If you have a two-handled compression faucet, you can release the cartridge by loosening and removing the retaining collar with locking pliers. Then, take out the valve from the valve housing and replace it.
