Replacing an Older TCV: 1/2 Inch vs 3/4 Inch Supply Inputs, the Hidden Deck-Plate Screw, the Governor Button and What Is Supplied

When an older thermostatic control valve (TCV) stops mixing properly, Ella's Bubbles supplies the complete TCV replacement valve assembly rather than a cartridge on its own, and the current valve uses 3/4 inch supply connections. If your original TCV has 1/2 inch supply lines, the new valve will fit once you add 1/2 inch to 3/4 inch NPT adapters. The chrome deck plate that covers the valve is held by four visible corner screws plus one hidden screw under the spout diverter, and the small button under the TCV handle is a governor that lets you go hotter than the preset. This article covers each of those points so you know what to expect before you start.

Does My Tub Have a TCV?

Depending on your faucet configuration, your Ella walk-in tub may include an Ella Thermostatic Control Valve that blends hot and cold water to your set temperature. Tubs ordered with the thermostatic faucet package have one; the dual-lever 5-piece fast-fill faucet and the single-lever 2-piece faucet are not thermostatic. The valve is the one furthest to the left on the chrome deck plate. If you are not sure which faucet you have, send a photo with your model and serial number and the team will tell you. The basics are in the thermostatic control valve explained.

Complete Valve Only

Two things the team is often asked about, answered plainly:

• Cartridges are not supplied separately. Support provides the whole TCV. The same is true of the diverter valves on the faucet set: there are no replacement cartridges for the diverters, but the whole diverter valve can be replaced, as covered in diverter valves and replacements.
• The older 1/2 inch valve is replaced, not refurbished. The earlier TCV with 1/2 inch supply lines is no longer carried, and the remedy the team offers for it is the current valve. If you would like to try cleaning a cartridge yourself first, Ella's Bubbles publishes a short cleaning sheet: grasp the cartridge top and bottom with channel locks (never by the rubber gaskets), unthread the two halves, remove the locking clip and shaft, clean every part with a brush and a mild solvent, then lubricate and reassemble in reverse order. The full procedure and the warranty facts around it are in TCV stuck or not mixing: cleaning and cartridge replacement.

Old 1/2 Inch Inputs Versus Current 3/4 Inch

The TCV that Ella's Bubbles carries today has 3/4 inch supply connections. If you are replacing one of the earlier 1/2 inch valves:

1. Confirm the size of your existing supply lines at the valve before requesting a replacement.
2. Plan on a pair of 1/2 inch to 3/4 inch NPT adapters so the new valve connects to your existing lines.
3. Ask the team for photos of the current TCV so you can compare it with what is under your deck.

A replacement valve is arranged through your Ella dealer or the team at (800) 480-6850, who will confirm the shipping address and which valve fits your tub.

Lifting the Chrome Deck Plate

To reach the valve you lift the chrome plate off the deck of the tub. It is held by the four visible screws at the corners of the plate and by a fifth screw hidden under the spout diverter valve, which is the middle valve on the plate. Remove that diverter handle to expose the center screw; the plate will not lift cleanly until it is out.

The Governor Button Under the Handle

This overview video describes the five-piece faucet set that comes with dual massage models. It explains that the set includes a thermostatic control valve that holds a safe fill temperature of 100.4 degrees, and that with a push of the button you can increase the fill temperature to your preference. It also shows the adjustable shower mixer on a 60 inch retractable hose and the handle extensions on the diverters that make flow adjustments easy. Watch: Top Voted Walk-In Tub for Independent & Luxurious Bathing with chapters and a full transcript.

A clarification the team gives often: the TCV does not have a separate locking mechanism. There is a governor underneath the handle, set at the factory to the safe preset, and you press the button to move the handle past that point. If the button is missing, the handle stays on one side of the governor and cannot be adjusted past it. The governor's position can be adjusted, and the team has a short TCV calibration video it will share on request.

Replacing or Servicing the Valve

Watch: Ella's Bubbles: TCV Valve Replacement with chapters and a full transcript.

Two details from the replacement video matter most for a swap. First, when the metal collar has to come off, put the channel locks or vise grips on the unthreaded flat wrench area of the collar so the threads are not damaged, then unscrew the collar completely before the cartridge comes out. Second, whenever the valve is open, check the intake screens and the check valve on the bottom, where sediment, salt and debris collect; a soft brush with CLR cleans them, and a light coat of lithium grease on the gaskets makes reassembly smooth. Tighten securely without over-torquing, then refit the escutcheon plate, washers, governor and handle in reverse order.

This is a straightforward job for a licensed plumber or a capable handyman. The published warranty asks that removal and cleaning of the TCV be handled by a licensed, insured contractor or plumber, and it also asks that the TCV be protected by an inline filter or mesh that is cleaned periodically, because cartridge fouling from calcium, iron or heavy particles in the water is not covered. See protecting the TCV with an inline filter.

Warranty Terms for the Valve Set

The TCV, which is the valve furthest to the left on the deck plate, carries a one-year limited warranty separate from the lifetime parts warranty. The diverter valves on the same plate carry the lifetime limited parts warranty, and a failed diverter is shipped under warranty after photos are reviewed. The exceptions are spelled out in warranty exceptions: the TCV, non-Ella faucets and water quality. Owners of much older tubs will find the legacy TCV regulator and other discontinued parts covered in parts and support for older Ella tubs.

The Current Valve Body Is Slightly Wider: Opening Up the Deck Hole

Besides the change to 3/4 inch NPT inlets, the current thermostatic valve body is slightly wider than the discontinued one. On an older tub it may not pass through the existing deck opening without a little trimming. The valve mixes hot and cold water to a set temperature exactly as the earlier valve did, so the changes are physical rather than functional and day to day use feels the same.

1. Shut off the hot and cold supplies to the tub.
2. Disconnect the supply lines and remove the old valve and its deck plate.
3. Test fit the new valve from below. If the body binds in the deck opening, mark how much more clearance is needed. It is usually about 1/4 inch.
4. Widen the opening a little at a time with a rotary tool, checking the fit as you go, and stop as soon as the valve passes through. Keep the cut small so the deck plate still covers the opening.
5. If your lines are 1/2 inch, thread the 1/2 inch to 3/4 inch NPT adapters onto the valve inlets, seal the joints, connect the supply lines and fit the deck plate.
6. Restore the water supply, check every joint for drips and set the valve to a comfortable temperature.

Both the adapters and the trimming are routine jobs for a licensed plumber, and technical support can answer your plumber's questions by phone. When you order, have your model and serial number ready. Some earlier tubs are listed under a current model name in Ella's records, so the serial number is the quickest way to match your tub to the right valve.

Related Guides

• Leaking Diverter or Thermostatic Control Valve: Identifying Your Faucet and Ordering the Right Replacement
• Tub Fills Only Scalding or Only Cold and Will Not Mix to Warm
• Cold Water Reaches the Tub but Will Not Come Out of the Faucet: Unlocking the TCV Check Valve
• What Should I Do When My Walk-In Tub TCV Fails After the Warranty?
• How do I set the maximum hot water limit stop on the Ella TCV?

Common Questions

For anything specific to your model, serial number or configuration, please open a ticket at ellasbubbles.com/support or call (800) 480-6850. The team is glad to help.