Moen Shower Faucet Won’t Turn Off? (6 Causes Explained!)

It is a frustrating issue if your Moen shower won’t stop running when you close it. You would try to close it a few times yet end up helpless with a dripping faucet. You might need to get help from a plumber or simply try to fix it yourself. This is a quick troubleshooting guide that helps you to figure out the possible issues and fix them. 

moen shower won't stop running
The Spruce / Kevin Norris

Why Won’t the Faucet Turn Off?

It’s common to find various issues in the household plumbing system. If your Moen shower leaks water after you turn it off, it is most likely to be due to a defective part. These are the possible defects and how you can fix them easily by following the steps closely.

1. Loose Faucet Handle

If you check closely, you will see a small screw in the shower handle that holds it in place. This screw needs to be at its tightest for the water to run without any leaks. If this screw is loose, it will not seal off the surfaces once you turn off the water. So, check this possibility and tighten the handle screw to stop the water. Here’s how to tighten the Moen shower handle in case it is loose:

  • Turn off the water supply from the main so that water doesn’t waste as you fix it.
  • Then uncover the screws under the cover plate on the shower handle using a flat-head screwdriver.
  • Tighten the hose screw clockwise using a Philip screwdriver.
  • Turn on the water and turn on the shower faucet to see if the problem is solved.

2. Stripped Handle

The other possible issue might be due to damages caused to the faucet handle. The faucet has a stem inside that regulates the water flow. A damaged handle will cause the water to run continuously even when you turn it off. If the Moen faucet has a stripped handle, the best solution is to replace it.

  • The first step is to turn off the water supply. 
  • Find a Moen shower faucet handle compatible with the existing one.
  • Uncover the screws under the cover plate using a flat-head screwdriver.
  • Loosen the screws using a Philips screwdriver.
  • Twist the handle gently and pull it out.
  • Install the new shower faucet handle and fix it in place by tightening the screws.
  • Replace the cover plate and turn on the water to check the function.

3. Clogged Faucet Handle

Debris or rust may cause obstructions in the faucet handle and keep the valve open. As a result, water will continue to flow even when you turn off the lever. Check for this possibility in your Moen shower faucet and clean the clogs.

  • Turn off the water supply and unscrew the faucet handle
  • Remove the handle and examine the inside for visible obstructions.
  • Brush away the debris and clean the faucet thoroughly.
  • Replace the faucet handle and tighten the screws.

4. Defective Shower Cartridge

The most common reason for a leaking Moen faucet is a faulty shower cartridge. The task of a faucet cartridge is to regulate the water flow and temperature in the water as you turn on the handle. If you find the faucet turned off but water still running, the cartridge could be worn out or damaged. A faulty cartridge will also avoid regulating the temperature. The only option, in this case, is to replace the defective cartridge.

  • Turn off the water supply and cover the drain to prevent any screws from falling into it.
  • Lift the cover plate using a flat-head screwdriver to access the screws under it.
  • Unscrew all the screws using a Philip screwdriver and remove the faucet handle.
  • Apply a thin layer of lubricant to the new cartridge and slide it in.
  • Insert the handle back and tighten the screws.
  • Replace the cover plate and turn on the shower to check.

5. A Faulty Shower Valve

The shower valve also supports regulating the water flow and temperature. So, a faulty valve will cause the water to flow continuously regardless of the closed state of the handle. You can replace the shower valve with the following steps:

  • Turn off the water supply and loosen the handle with an Allen wrench.
  • Take out the handle, and remove the faucet stem and the washer.
  • Examine the washer to see whether it is old and worn out.
  • If so, replace it with a new valve and reassemble the faucet.
  • Turn on the water supply and check the flow of the faucet.

6. Worn-out Stem Washer

Check whether both the tub and shower faucet run simultaneously even after you turn them off. If this is the case, the problem is most likely to be in a defective diverter valve. The function of the diverter valve is to regulate the water flow between the tub’s spout and the shower so that only one runs at a time. 

  • To replace the diverter valve, first, you need to turn off the main water supply. 
  • Unscrew the Moen diverter valve and remove it.
  • Check and remove any debris clogging inside.
  • If the valve is not damaged, insert it back after cleaning.
  • But if it is damaged, you need to replace it with a new one.
  • Make sure to get the suitable Moen diverter valve compatible with the faucet.

Frequently Asked Questions

What Do You Do When Your Shower Won’t Turn Off?

The first step is to examine inside the faucet to clear any debris accumulations. Sometimes you may not be able to fix the issues easily with straightforward replacements. If so, you should call a plumber to get advice on the matter. They can diagnose problems easily even if it is a serious case. They will also help you to avoid these issues in the future. 

How to Maintain a Shower?

You will experience frequent malfunctions in your shower if you don’t clean and maintain it appropriately. Prepare a gentle cleanser using baby shampoo and water. Dip a soft nylon brush in the solution and wipe the showerhead. Remove any clogs in the spray jets using a calcium and lime solution. If you need to change your showerhead, select one with rubber tip jets as it’s easy to clean them simply by wiping with a cloth.

Why Do Moen Cartridges Go Bad?

Faucet and shower cartridge failures occur due to the drying up of the rubber O ring inside the faucet or valve. It also happens if the passages in the cartridge are blocked. The cost to replace a shower cartridge is around $100 – $350. The cost of a faucet cartridge ranges from $10 to $80 depending on the brand and type of valve. The labor cost charged by a plumber is around $90 – $270.

Conclusion

Now you can fix the issue if your Moen shower won’t stop running even after you turn it off. Restore the shower soon so that you don’t let water waste. If you have trouble replacing the parts, you can get a professional to do it. They will help diagnose the issue, fix it, and advise you on how to prevent it from happening again.