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Leaking Diverter or Thermostatic Control Valve: Identifying Your Faucet and Ordering the Right Replacement

Updated September 2026

▶Glossary9
  1. Which Part Is the Problem?
  2. Send a Photo Before You Order
  3. What Actually Ships
  4. Warranty Coverage on Faucet Valves
  5. Having the Valve Installed
  6. Related Guides
  7. Related Videos
  8. Common Questions
  9. Still Need Help?

If a diverter handle on your Ella walk-in tub drips, runs while the tub is not filling, or will not shut off, the fix is a replacement diverter valve. If a thermostatic faucet no longer delivers hot water or will not hold its set temperature, the fix is a replacement thermostatic control valve (TCV). Ella tubs have shipped with more than one faucet style, so before a part is ordered the team asks for a photo of your faucet deck along with your model and serial number to match the right valve to your tub.

Which Part Is the Problem?

An Ella thermostatic faucet package has a temperature control valve that mixes hot and cold water to the temperature you set, plus diverters that send water to the tub spout and to the hand shower. The symptom usually points to one of them.

  • Water seeps or runs from a handle while the tub is sitting idle, sometimes badly enough that the supply has to be shut off at the main. This is a cracked or worn diverter, and the fix is a new diverter valve.
  • A handle will not stop the flow after a bath. This is also a diverter fault.
  • The spout or hand shower never gets hot on a thermostatic faucet. This points to the TCV, whose cartridge picks up minerals from the water over time. The cleaning steps are in TCV cartridge cleaning and replacement. If cleaning does not restore hot water, the valve is replaced.

Not every Ella faucet includes a TCV. If your deck has separate hot and cold handles and no single temperature dial, there is no mixing cartridge, and a temperature complaint is traced to the diverters or to the home's water supply instead.

Send a Photo Before You Order

The same model tub may carry a different faucet depending on when it was built, and the wrong valve will not fit. The team identifies your faucet from a picture together with your model and serial number.

  1. Photograph the faucet deck from above so every handle and the spout are visible. If you can reach the underside through the access panel, a second photo of the valve bodies helps.
  2. Find your model and serial number on the label behind the magnetic access panel beside the door.
  3. Open a ticket at ellasbubbles.com/support with the photos, a short description of the leak or temperature problem, the serial number, and your contact and shipping details. You can also call (800) 480-6850 and send the photos when asked.
  4. The team confirms which faucet you have, looks up the warranty on your order, and tells you whether the part is in stock or has to be ordered.

The steps are the same as for any other part and are described in how to order replacement parts.

What Actually Ships

A replacement diverter ships as a complete valve. The thermostatic control valve ships as a complete valve assembly rather than a bare cartridge. Mineral scale collects inside the old valve body as well as in the cartridge, and a fresh cartridge dropped into a scaled body has a shortened life, so the whole valve is supplied.

The current TCV has 3/4 inch supply inlets and a slightly wider body than some earlier versions, and it works the same way once installed. If your tub was plumbed with 1/2 inch supply lines, your plumber fits 1/2 inch to 3/4 inch threaded NPT adapters, and the deck opening may need to be widened by about 1/4 inch to pass the new valve body. The fit details are in TCV replacement fit and supply adapters. If you are near Chicago, parts can also be collected, as described in picking up in Chicago.

Warranty Coverage on Faucet Valves

Ella's lifetime limited parts warranty covers the faucet for the original purchaser at the original installation address, and the team looks your order up by the name and email on the purchase. When a part is covered, it ships at no charge for the part. The thermostatic control valve is the exception. It carries a 1-year limited warranty, and cartridge fouling from calcium, iron or contaminated water is not covered, so an inline filter or mesh screen must be fitted on the supply and cleaned periodically. If your tub is outside coverage, or you are not the original owner, contact your Ella dealer or the team at (800) 480-6850 to arrange a replacement valve.

Having the Valve Installed

Ella ships the part and does not send a technician. A local licensed plumber does the swap along with any adapter or deck work. If a diverter leaks constantly, the water may need to stay shut off at the main until the new valve is in. Guidance for the whole faucet set is in replacing a walk-in tub faucet set or hand mixer.

Chapters in this video
  1. 0:00 Remove Handle And Collar The technician removes the colored cap, loosens the bolt with an Allen wrench, and lifts off the handle, then removes the plastic collar.
  2. 0:19 Remove And Clean Cartridge The technician uses a socket wrench to loosen and remove the cartridge, then checks for debris and cleans it with a soft brush.
  3. 0:37 Replace Cartridge And Collar The technician replaces the cartridge, tightening it without over-torquing, and then replaces the plastic collar.
  4. 0:51 Reattach Handle And Cap The technician puts the handle back on in the correct position, tightens the Allen bolt firmly, and replaces the colored cap.
Chapters in this video
  1. 0:00 Remove Control Handle And Cover The technician removes the control handle and cover plate after shutting off the water supply.
  2. 0:16 Remove Escutcheon Plate And Collar The technician removes the washers, escutcheon plate, and then unscrews the metal collar.
  3. 0:33 Unscrew Cartridge And Clean Screens The technician unscrews the cartridge and cleans the intake screens and cartridge bottom.
  4. 0:56 Replace Cartridge And Reassemble The technician lubricates and replaces the cartridge, then reassembles the collar, escutcheon plate, and control handle.
  5. 1:30 Inspect Water Intake Screen The technician inspects and cleans the water intake screen and check valve for calcification and debris.

Common Questions

Can I buy just the cartridge for the thermostatic control valve?
The TCV is supplied as a complete valve assembly, not as a bare cartridge. Scale builds up inside the old valve body as well as the cartridge, and a new cartridge in a scaled body wears out early. If your problem is a stiff or dripping handle on a fast-fill faucet rather than a TCV, see faucet cartridge replacement.
How do I know whether my tub has a thermostatic faucet?
Look at the deck. A thermostatic package has one temperature control that mixes hot and cold, plus diverters for the spout and the hand shower. If you have separate hot and cold handles instead, there is no TCV on your tub, and a photo of the deck lets the team confirm this for you.
Will the current TCV fit my older tub with 1/2 inch lines?
Yes, with two small changes. Your plumber adds 1/2 inch to 3/4 inch threaded adapters on the supply lines, and the hole in the deck may need to be opened up by about 1/4 inch because the current valve body is slightly wider. The valve works the same way once installed.
Is a leaking diverter covered by the lifetime warranty?
The faucet and its valves are part of the lifetime limited parts warranty for the original purchaser at the original installation address. Send photos and your serial number and the team verifies coverage on your order. Labor to install the new diverter is not covered and is done by your local plumber.
Why do I need to send a photo if I already know the part I need?
Ella has used several faucet designs over the years, and the same model tub may carry different faucets depending on when it was built. The photo, with your model and serial number, prevents the wrong valve from being shipped. It also lets the team see whether you have a TCV package or a faucet with diverters only.

Still Need Help?

Open a ticket at ellasbubbles.com/support or call (800) 480-6850 and have your model and serial number ready.

Related guides

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