To replace a faucet cartridge on an Ella walk-in tub, you remove the handle, take off the parts that hold the cartridge down, lift the old cartridge out and seat the new one. The exact steps depend on whether your tub has the 2-piece fast-fill faucet, the 5-piece fast-fill faucet or a thermostatic control valve. If you are not sure which faucet you have, What Is a Hand Shower Diverter on a Walk-In Tub? describes how the sets differ, and the two videos on this page show the 2-piece and 5-piece replacements from start to finish.
First, Identify Your Faucet and the Right Cartridge
Three different cartridges are used across Ella faucet packages, and each one comes out a different way. Your order tells you which faucet package your tub was built with, and the faucet itself confirms it:
- 2-piece fast-fill faucet. A spout with a single lever handle on top and a diverter button under the spout. It has one cartridge, under the spout handle.
- 5-piece fast-fill faucet. Separate hot and cold handles with a middle diverter lever between them. Each handle has a red or blue cap and its own cartridge underneath. This faucet is not thermostatic.
- Thermostatic faucet package. A temperature dial with a built-in Thermostatic Control Valve, or TCV, that blends hot and cold to a set temperature. Its cartridge is the thermostatic one, and tubs with this faucet on a chrome deck plate have two diverter valves as well.
Make sure the cartridge is really the part at fault. Trouble switching between the spout and the hand shower points to the diverter, which is a separate valve that is supplied complete when it truly needs replacing. Water that runs hotter than the setting, or jumps between scalding and cold, points to the TCV cartridge on a thermostatic faucet. Before any cartridge comes out, close the hot and cold shut off valves at the tub.
Replacing the Cartridge on the 2-Piece Fast-Fill Faucet
The first video shows the whole job on the 2-piece faucet, including the exact Allen wrench size to use. The steps it shows are:
- Remove the decorative bolt cover on the handle, insert the Allen wrench and loosen the Allen bolt.
- Lift off the spout handle.
- Unscrew and remove the escutcheon plate.
- Loosen and remove the brass locking collar.
- Lift the cartridge straight out.
- Set the new cartridge in place so its two guide posts line up with the receptacles in the spout housing. The cartridge seats correctly only when both guide posts are in the correct position.
- Replace the brass locking collar and tighten it securely without over torquing.
- Replace the escutcheon plate and hand tighten it.
- Put the faucet handle back onto the top of the cartridge and tighten the Allen bolt securely, again without over torquing.
- Replace the bolt cover. The red side should be on the left for hot and the blue side on the right for cold.
The guide posts are the detail to watch. If the cartridge does not drop fully into the housing, lift it, turn it until the posts find their receptacles and try again rather than forcing the collar down over it.
Replacing a Cartridge on the 5-Piece Fast-Fill Faucet
On the 5-piece faucet, the hot and cold handles each have their own cartridge, so you only open the side that needs attention. The second video shows these steps and names the Allen wrench and socket sizes:
- Remove the red or blue cap on the handle.
- Loosen the bolt with the Allen wrench and lift off the handle.
- Remove the plastic collar under the handle.
- Use a socket wrench to loosen and remove the cartridge.
- Check for debris, foreign objects or calcification. If needed, clean with a soft brush and rinse.
- Install the cartridge and tighten it. Do not over torque.
- Replace the plastic collar.
- Put the handle back on, making sure it faces the correct position, and tighten the Allen bolt firmly without over torquing.
- Replace the colored cap.
Step 5 is worth a pause. The video treats inspection and cleaning as part of the job, so a cartridge that is only carrying debris or calcification can sometimes be cleaned, rinsed and put back.
Cleaning or Replacing the Thermostatic (TCV) Cartridge
The thermostatic cartridge is the one most affected by water quality. Calcium, iron and sediment in the supply foul it, and a fouled cartridge can cause several different symptoms: water hotter than the setting, covered in Why Is the Water in My Walk-In Tub Too Hot?, water that will not blend at all, covered in Tub Fills Only Scalding or Only Cold and Will Not Mix to Warm, or hot and cold crossing over when the tub is off, covered in Why Does the Mixing Valve Cross Hot and Cold When the Tub Is Off?. Have a licensed and insured plumber do this work. The sequence is:
- Shut off the hot and cold water supply to the tub.
- Remove the control handle and cover, then the washers and escutcheon plate.
- Unscrew the metal collar and remove the cartridge.
- Clean the intake screens and the cartridge of calcification, reinstall and test.
- If cleaning does not solve it, fit a new cartridge and reassemble without over torquing.
- Open both shut off valves fully and confirm that the fill temperature responds normally.
One exception saves an unnecessary cartridge change. If the faucet delivers only hot water no matter where the dial is set, and the cold line has pressure, the cause is usually the check valve at the cold inlet rather than the cartridge. Cold Water Reaches the Tub but Will Not Come Out of the Faucet: Unlocking the TCV Check Valve walks your plumber through that fix. If the valve itself has failed, replacing the whole TCV is the recommended repair.
Getting the Part, and Protecting the New Cartridge
Ella faucets are covered as supporting equipment under the Lifetime Limited Warranty, which is a parts warranty. The TCV is the exception: it carries a 1-year limited warranty, and cartridge fouling from calcium, iron or contaminated water is not a covered defect. When a part is covered, it ships under the warranty and a local licensed plumber does the labor. Ella does not send technicians.
To request a cartridge, open a ticket at ellasbubbles.com/support or call (800) 480-6850, and have your model, your serial number and a photo of the faucet ready so the right part is matched to your tub. After a thermostatic cartridge is cleaned or replaced, fit an inline filter or mesh on the water lines and clean it periodically, so scale does not foul the new cartridge. That protection is required for the TCV. If cleaning the cartridge becomes a recurring chore in your area, tech support may suggest moving to the Ella 5-piece fast-fill faucet, which mixes with manual hot and cold handles and has no thermostatic cartridge to foul.


Watch: Ella's Bubbles: Cartridge Replacement 5 Piece with chapters and a full transcript.
Related Guides
- Why Does My Tub Faucet Drip Constantly and How Do I Fix It?
- Why Does My Faucet Handle Keep Falling Off?
- Temperature Control Valve (TCV) Stuck or Not Mixing: Cleaning the Cartridge and Replacing the Valve
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