How To Replace a Shower/Tub Cartridge For The First Time

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Water fluctuations and sudden water pressure drops in the shower are familiar complaints. The culprit is certain, and we have the blueprint. Here's what you need to do.
Broken shower cartridge

Your first time?! You’ll always remember it. FOREVER!

But, how do you pull it off, how to replace a shower cartridge yourself?

Let’s go over it. Together.

A straightforward process.

And the good thing! A new shower faucet cartridge won’t cost more than a hundred bucks and, most of the time, it’ll be plenty lower. 

On the other hand, getting a plumber will cost more than that. That’s why replacing your own shower cartridge is the more practical option, especially if it’s unplanned and you have a budget set for it.

Not to mention…

…it definitely pays to know what you’ve got underneath your bathroom fixtures, their system, and how they work so you can confidently fix them yourself should any petty issues come up in the future.

Replacing your shower cartridge may sound like a mess waiting to happen for the inexperienced. But it’s actually very easy, even for beginners.

Below are very easy-to-understand steps on how to replace your shower cartridge, along with other information that you’ll want to know as a homeowner.

Read on to see how.

Table of Contents

Tools Needed To Replace Shower Cartridge

Tools for shower cartridge replacement

  • Big screwdriver and small screwdriver (flathead screwdriver)
  • Allen wrench/ Hex wrench
  • Pliers
  • Cartridge puller or a cartridge removal tool
  • New shower cartridge of the same brand or model as your old one 
  • Silicone grease
  • O-rings and watertight seal for the flange (if it doesn’t have one yet)
  • Cover for your workspace

Step 1: Remove the Faucet Handle

Removing the faucet handle

Hold up right there.

Before anything else, you may want to cover your shower drains first.

If you’re working on a bathtub cartridge, cover the surface of your bathtub too. The cover for catching any fallouts or debris that could collect as you work on your shower cartridge. 

If you’re not careful with this matter, the tiniest fallout may end up blocking your shower drainage system or even scratching your bathtub. 

After that…

To start off with replacing the cartridge, the first thing you want to do is to remove the handle or level of your shower faucet

Commonly, shower faucets have a screw in the handle’s middle part. But if yours come in a different design, just find the attaching screw and remove it.

Step 2: Remove the Escutcheon Plate

Removing the escutcheon plate

Okay, enough of the fancy words. Escutcheon is the metal plate that covers the hole where your shower cartridge or shower valve (and basically, your plumbing system) is installed.

Usually a chrome sleeve, it helps with the aesthetic of your trim kit by covering the unsightly parts. But aside from that, it also serves as a carrier for the other components of your kit, such as the handle itself.

It’s also sometimes called a flange.

Just like the faucet handle or lever, remove this plate by unscrewing it with the same screwdriver. 

You can also run the perimeter of the plate with a knife or something equally sharp to get it ready, so prying it out would be much easier.

Step 3: Turn off the Water Supply

shower wall cartridge

Now, before doing anything else, you have to turn the water supply off first. You don’t want a sudden blast of water hitting you on the face as you remove the faucet cover, do you?

Worst-case scenario, you could get scalded with hot water if your water supply isn’t turned off upon disassembling your shower faucet.

Some cartridges have water shutoffs in both hot and cold water supplies. But if you own a relatively old shower faucet cartridge, which is fairly common, there’d be no shutoffs.

In that case, you’d have to go and shut down the water supply of the whole house.

Step 4: Remove the Shower Valve Cartridge

Removing the shower cartridge

Now, the plumbing system is out and bare for you to work on. 

In case you haven’t done this before…

…and if this is the first time your shower cartridge is opened, this is the time to inspect what kind of cartridge type you have. It could be a ball type, a simple linear cartridge, or a valve.

The cartridge should be located just under where you pulled the shower handle out. 

Now, remember this: if you’re dealing with a very old shower unit to replace it with a new cartridge, you want to be as careful as possible.

Some components may break if you’re reckless in removing the old cartridge. In the worst-case scenario, the whole system could break, and you’d then have to get the whole shower unit fixed.

On the other hand…

…assuming that you already have a new shower valve cartridge replacement kit with you, you can now get your tool and carefully remove the cartridge. 

But before that, you have to remove the cartridge retaining clip first.

It’s a small clip that holds the cartridge in place. It could be made of tough plastic, but it’s usually a thin metal.

Use an Allen wrench (a disposable version also sometimes comes with a replacement cartridge kit, too) to pry it out. Again, be very careful. You don’t want to break the clip as you’ll have to put it back after.

Set the clip aside and start taking the shower cartridge out.

Some shower cartridges usually come with a cartridge removal tool or a cartridge puller. All you have to do is attach it with the cartridge, matching up the teeth (it should have teeth that are made according to the design of the shower cartridge). 

After inserting it, I like to slowly twist it around like a warm-up. This is to kind of break the old adhesive that’s binding it to the shower system while shaking the cartridge loose.

Now, it should be ready and easier to take out.

Slowly and carefully pull the cartridge out. 

Step 5: Install the new Cartridge

Shower cartridge assembly

After taking out the old cartridge, you can now insert the new one.

But before that…

…you can also take a look to see if there’s any mineral buildup inside your shower faucet unit. It’s not uncommon, especially if you’re working with a very old unit.

You can choose to do a little cleanup before installing your new shower cartridge. A small wipe of vinegar helps remove these mineral deposits that could potentially cause damage to your shower unit in the long run.

And that’s not all.

You can also look for parts that are already worn out and broken, such as o-rings. A broken o-ring could cause leakage, and we can’t have that.

Take new o-rings and replace the old ones if necessary. In case you’re wondering, you can find them in your local plumbing supply stores or home centers. 

After that, don’t forget to dab a good amount of silicone grease around the cartridge to act as a lubricant. You can also put some on the o-rings to reduce friction and help it stay intact for a long time. 

Now, off your cartridge go.

Step 6: Insert the cartridge retaining clip

Installing new shower cartridge

Now, you should be gentle with putting the new shower cartridge in as much as you did when taking out the old one.

Once the new cartridge is snug and fits inside the system, you can now put the retaining clip back.

This component may look like an insignificant accessory, but it’s very important in holding the cartridge down in its position in the years to come. 

A misplaced shower cartridge could pose a problem for you in the long run, such as switching cold and hot water lines and even harm and injury caused by this.

Use a wrench to be accurate when putting it back into its place. 

Step 7: Turn the cartridge to the off position

Shower cartridge off position

You’re not done with the internal parts just yet!

Before putting the shower trim kit back, make sure to turn the shower cartridge in the off position first. 

Use a wrench or pliers to twist it counterclockwise until the notch faces the floor. 

Step 8: Re-install the faucet trim kit

Before putting the escutcheon back, you can also get a stop tube or sleeve to put in its perimeter. 

Some old single handle shower valves don’t have one, but you can definitely buy and put one on the plate.

This will help keep leaking at bay. 

Step 9: Reinstall the handle

Reinstalling the shower faucet handle

Once the cover plate is back and screwed in place, you can then put the shower handle back in. If your faucet body has a shower handle adapter, it goes first and then the actual handle.

But before that, make sure to twist the handle adapter (if your faucet has one) to 180 degrees. This is to turn the side with the hole for the screw to face down. 

Why is this?

You’d want the OFF position to be facing down with a positive stop. 

Now, screw the handle tight in place with care using an Allen wrench. 

Step 10: Try your new cartridge installation

Clean up your workspace. Sweep out all the debris and fallen pieces, if there are any. Make sure that there’s nothing left, as single tiny debris could potentially clog your drainage.

Remove the covering and test out your new replacement cartridge!

Turn the main water supply line on and test the faucet out. Observe the temperature and see if it’s as hot or as cold as it should be.

Now, in some instances…

…the hot and cold water supply lines could switch. In that case, all you have to do is unscrew the handle and twist the core to 180 degrees.

In testing out your new cartridges, be sure to open another water outlet, too. It could be your kitchen sink faucet, the dishwasher, or a toilet flush. Do it while your shower is open and see if the water temperature will change.

It should stay consistent and steady. 

How would I know if my shower faucet cartridge needs replacing?

Now you know how to replace a shower valve cartridge by yourself. 

But the question is…

…should you?

For starters, a shower cartridge is a type of shower valve that regulates water flow and temperature.

It’s located inside your shower faucet, and you’ll know that it’s the cartridge when you see holes. It has a hole for hot water, and it has another for cold water.

A shower cartridge works whenever you pull or turn the handle to turn the water on or off or to adjust your shower temperature.

This way, the flow of either hot or cold water is regulated to give you the temperature that you’re looking for. 

Shower cartridge assembly

Now, when should you replace your shower cartridge?

As the saying goes: “don’t fix what isn’t broken.”

The same goes with your shower cartridge. But if you’ve just moved to a house with a very old, barely working one, then you definitely should!

Aside from that, here are a few signs that you need a new replacement cartridge ASAP.

  1. Your shower runs cold. Does your nice warm shower don’t last long anymore and would turn cold after a few minutes? Or perhaps, it just easily runs cold whenever someone in the next room turns on the water? 

This one is the most common sign of a broken shower cartridge that needs replacing as soon as possible. 

An unstable temperature could be very dangerous and could cause scalding or accidents due to shock with a sudden and drastic change in temperature.

  1. A tight handle. Another sign of a bad shower cartridge is a shower handle that works irregularly. Sometimes, it’s the way your shower handle becomes unusually tight that it’s getting harder to turn it every time.

It could also come in the form of noise whenever you twist or turn it, or worse, the entire thing slipping or falling down from the faucet.

  1. A drop in water pressure. Another common sign is a change in water pressure. It could be a drop in cold water supply, a drop in hot water, or just the stoppage of water pressure altogether.
  2. Water doesn’t get hot at all. Or it gives the wrong temperature and is not what you set it or turned the knob for. In some instances, the water just gets straight up freezing cold. It could very much be a cartridge problem. 

How to Replace Shower Cartridge: Things to Remember

Being one of your faucet’s most important components, buying a replacement cartridge (or other replacement parts for that matter) shouldn’t be a walk in the park. 

And you shouldn’t just randomly get a generic one, too. 

Below are just some of the things you’d want to remember when replacing your shower faucet cartridge.

Be aware of its brand and manufacturer. There are lots and lots of cartridge brands and models on the market today. 

That being said, we don’t just get one and expect it to fit in our house plumbing system, as well as your pre-existing shower unit.

Knowing the exact brand and unit of your shower cartridge can do more than give your shower consistency.

As a matter of fact, it could give you some free stuff too!

Well, not really free, but some manufacturers offer a lifetime warranty on their products, so after you find out the model of your cartridge, you can get the manufacturer’s contact and ask them about it!

As a cartridge could have different variations depending on how the company manufactured it, you can just ask them where to buy the same exact unit. Saves you more time and energy.

shower cartridge replacement without turning off water

As for the orientation of the cartridge…

…in case you’re lost as to how to properly place the new one, you can inspect the cartridge and look for hints. Usually, it would have arrows pointing up. That’s a symbol pointing you in the right direction the cartridge should be installed.

Now, this is where the awareness of your old cartridge’s brand and model comes in. By knowing this piece of information, you can search for its particular instruction manual, which you can use in replacing your shower cartridge.

Check the status of your shower and cartridge. Maybe, just maybe, you really don’t need a new cartridge. Maybe it’s just overburdened with mineral deposits or worn-out o-rings and washers.

To check, follow the instructions mentioned earlier to open your faucet unit up.

Take your cartridge out and check for mineral build-ups. If there’s any, soak the cartridge up in vinegar to dissolve the deposits. 

That should effectively clean your cartridge. If there’s no other issue, it should work like new. 

If you live in an old house and the washers are already worn-out and broken, just get new ones from your local hardware store. 

Conclusion: How to Replace a Shower Cartridge

Single handle shower faucet cartridge

There’s no doubt about it: knowing your home plumbing system makes a big difference not only in fixing any sudden issues that may come up but also in cost-cutting!

Nowadays, a plumbing service could easily cost you a couple of hundred dollars for something so simple as taking out a cartridge!

To be fair, most houses in the states still have the earliest models of shower faucet cartridge (or the ever-popular Moen shower cartridge with the single lever). That makes it extra crucial when replacing it. 

That’s why it’s also important to be aware of and follow manufacturer’s instructions, too.

Aside from the cartridge, you can also add anti-scald valves on your faucet as an extra safety precaution.

And most of all…

…don’t forget to maintain and do regular checkups to ensure that your shower unit is in tip-top shape that’s safe for everyone!