How to Fix a Leaking Shower Faucet

If your shower leaks or drips from the faucet (handle), this is due to a spoilt Shower Cartridge Valve located inside your shower faucet assembly. This is a common problem in older properties. Here’s what you have to do to :

1. Disassemble your shower faucet
2. Replace the cartridge 
3. Put everything back together. 

If the leak is left untreated, it will worsen over time, making annoying drip sounds, increasing your water bill and potentially damaging other parts of your bathroom in the long run. I will teach you how to DIY repair this problem from my own frustrating experiences so you can save money, gain experience, minimize property damage and impress the family with your handyman skills, all at the same time. Total win. 

What is a Shower Cartridge Valve?

The Cartridge Valve’s job is to turn the shower water on/off and control the mixture of hot and cold water to provide your desired water temperature based on how you turn the handle. Over time due to wear and tear, and erosion under strong hot water pressure and build up of hard water residue, the internal parts lose its ability to form a seal and hence resulting in a leaking/dripping shower.

Note that there are several design types of this valve and this is what my Shower Cartridge Valve looks like. It is important for you to know how it works so you can remove it from the assembly and properly reinstall it back. Read How a Shower Cartridge Valve Works.

Difficulty Level 

This DIY project has a high difficulty rate if you do not know what you are doing. I will rate this project based on the user’s experience level so you can gauge yourself:

BEGINNER: If you have never done this before and have to figure this out all on your own: Difficulty level is at least 8/10 – At least 1 hour

NOVICE: Maybe you’ve seen someone else doing it but haven’t done it yourself: Difficulty level is at least 6/10 – Around 30-45 mins

EXPERIENCED: You know what to do and have done it before at least once: Difficulty level is at least 3/10 – 15 mins

As with most things in life, this project will get easier with proper guidance and experience. The goal of this article is to lower your difficulty level for the first timer out there so you don’t have to figure it all out on your own as I did (I paid a plumber to see what he did and jumped to Novice).

What you Need – Tools for the Job

1. New Shower Cartridge Valve (bring your damaged one to the hardware store and get something that is compatible).
2. Adjustable Pipe Wrench
3. Adjustable Pliers
4. A big sturdy flat head screwdriver
5. A small flat head screwdriver (test pen will do)
6. A box cutter knife (optional)
7. Small torchlight or a cell phone light will do

Detailed Step by Step

STEP 1: Cutting Off Water Supply to the affected Bathroom

Before you do any work in your bathroom, Turn off the water supply to the bathroom or else you will get water sprayed all over the place. The bathroom water supply is usually on the wall in the same bathroom. If you can’t find it, or the valve doesn’t work, you have to turn off the main water supply valve of your home. In a landed house, it is usually outside, in an apartment, it is in the riser room of your floor. You might need to ask your building manager to access it. Then, go back to your bathroom and make sure no more water is coming out of the shower when you turn the handle on before you proceed.

STEP 2: Taking the Shower Handle Off

The shower handle has a female connection and the cartridge valve has a male connection. All you need to do is to remove the screw tying these two together and pull the handle out.

Depending on your shower handle model, the hole accessing to the screw might be plugged with a decorative plastic cap. The best tool to pry the plastic cap open is a small screwdriver (test pen).

Tip: If the plastic cap is too flushed to the handle, you will find that the screwdriver head can’t fit in between the gap. This is when you use a box cutter knife. The blade is thinner and could go in between the cap and the handle (but is also weaker). Use the knife blade to slowly and carefully create a bigger gap so that the head of the test pan can fit through to do the actual prying. Be careful not to hurt yourself in the process.

Once you have the plastic cap removed, use a small torchlight or your cell phone light to see the type of screw head that you have to deal with. Use the correct screwdriver to unscrew it.

If you can remove the screw without any drama, you just have to jiggle and pull the handle out from the assembly. Be careful not to pull too hard that the handle flies off and possibly hitting other things (like the expensive glass wall).

If you can do it this way, congrats, you just skipped the hardest part! If you can’t get the screw out, this is going to be a little tough.

Help! The handle is stuck!

The hardest part of this project is if you can’t pull the handle out from the shower assembly, possibly due to:

1. The screw head holding the handle to the plastic cartridge is worn out (stripped screw). Your screwdriver just slips off the screw head, and therefore unable to release the connection between the two.
2. Even if you can get the screw off, the handle might simply be stuck with all the hard water residue buildup over the years.

At which point, you have a high chance of flipping out (I know I did) because you need to figure out a way to forcefully remove the handle without damaging other things in your bathroom. 

Here’s what happened to 2 of my showers: The mentioned screw head is worn out (stripped screw). As I turn the screwdriver, it just slips off the screw head. There’s no way I could turn the screw! unless if I have a special stripped screw remover tool, which I don’t, and even if I did, it will most likely not fit in the hole.

How to break the connection between the cartridge and the handle

You have to shear off the plastic male part of the cartridge. 

• Get your medium-sized, sturdy flathead screwdriver, and something to hammer the back of the screwdriver with (hammer or the heavy adjustable wrench).
• Close the handle so the neck of the handle is most exposed.
• Slowly slide the screwdriver at 12-0-clock and slowly start tapping in to bend the dome-shaped metal cover. You need to bend it a bit so you can see the plastic male connection of the cartridge that needs to be sheared off.

• Once you can see the male plastic connection of the cartridge, position the screwdriver head on the plastic male part of the cartridge (as close to the wall as possible) and start hammering the back of the screwdriver. Do this until you shear the connection.

• Now you will realize that there’s a piece of the plastic cartridge stub still lodged in the female connection of the metal handle:

• Grip the end of the plastic with an adjustable plier and ask a friend for help to slowly hammer the handle to free the stub.

Congratulations! You have passed the hardest part of the process.

STEP 3: Replacing the Cartridge

Now that the handle is free, remove the bent metal dome using an adjustable wrench. Turn counterclockwise. Don’t worry if it’s too damaged. I didn’t even bother to reinstall it.

Next, you need to remove the nut that locks the cartridge into the wall assembly. Use the adjustable wrench again to grip and twist counterclockwise to release the nut.

Take the old cartridge out:

Now get your new shiny cartridge and take a look at the holes to see how they align to your shower. On the cartridge, there are 2 positioning extrusions. These should align into the 2 positioning holes in the shower wall assembly:

With the correct alignment, place the new cartridge in and push it as much as you can. They, wiggle it about clockwise and counter-clockwise to make sure the positioning holes and extrusions are properly positioned and connected. If done correctly, you won’t be able to move the cartridge body:

STEP 4: Putting it all Back Together

To finally form the seal, you need to put the nut back on to apply pressure to the O-Rings. 

Before you put the handle back on, try to reopen the water supply and play around with the valve. There should be no more leaks if the shower is in the off position.

If all is good, reinstall the metal dome if it’s not too damaged. It is only for decorative purposes and I damaged mine too much as I used adjustable pliers and not an adjustable pipe wrench. The pliers did not grip the dome well and just destroyed it pretty much. so I just tossed the metal dome in the garbage. The shower handle does not look weird so it’s fine.

Lightly tap in the handle and the plastic male-female connection. I would advise you to not hammer it in too tight or else it will be too hard to take it back out if you need to change the cartridge again in the future.

Wrapping It All Up

That’s it! It gets easier the more you do it. Hopefully, this guide has been useful as I could not find this when I needed it.

Check out the Airbnb unit that I managed that I had to change the shower Cartridge Valve: