How do I set the maximum hot water limit stop on the Ella TCV?

The maximum temperature on an Ella Thermostatic Control Valve is set by a spring-loaded locking pin inside the control handle that rests against a locking collar, and you change it by removing the set screw cover, loosening the set screw with an Allen wrench, and re-seating the handle on the brass fitting at the position you want. The valve leaves the factory set at 100.4 F, and Ella's published guidance is that it can be adjusted downward while turning it above that setting is not recommended, as What Is a Thermostatic Control Valve (TCV) on a Walk-In Tub? explains. The first video on this page shows the adjustment step by step on the valve itself.

First Confirm Your Tub Has a TCV

The TCV comes with the Ella thermostatic faucet package rather than with a particular tub model, so two tubs of the same model can differ. The dual-lever 5-piece fast-fill faucet and the 2-piece fast-fill faucet are not thermostatic, and on those faucets you set the temperature by hand at the levers every time, with no limit stop to adjust. Look on the deck for a separate temperature handle with its own governor beside the faucet, or check your order confirmation. If your configuration has no TCV and you want a fixed maximum, a qualified contractor can add an external temperature-control valve on the hot water line, though that may reduce flow and lengthen the fill.

How the Limit Stop Works

Hot and cold supply lines feed into the valve, and a cartridge inside blends them to the temperature the handle is set to. If the cold supply drops, the valve limits the hot flow, and if the hot supply drops, it limits the cold, so the water at the spout stays steady. The limit stop is mechanical. Inside the TCV handle is a spring-loaded locking pin, which is the anti-scald mechanism. The pin sets against the locking collar, and the button must be pushed to move the handle toward hotter water. When the valve is set at 100.4 degrees, the button springs back, which is how you can tell the handle is at the factory position. Everything above that position is deliberately harder to reach, because a walk-in tub bather cannot step out of the way of a temperature spike until the tub drains.

Step by Step: Resetting the Preset on the Handle

The Ella video on TCV temperature adjustment shows this sequence, and it needs only the set screw cover, an Allen wrench and the handle.

1. Remove the set screw cover from the TCV handle.
2. Loosen the set screw with an Allen wrench.
3. Look inside the handle for the spring-loaded locking pin that sets against the locking collar. This is the anti-scald mechanism, so handle it gently.
4. Place the handle on top of the brass fitting and turn it to the warmer water position.
5. Briefly take the handle off the brass fitting, then reset it, turning the handle a quarter turn counterclockwise. In the video this allows more hot water to flow through the valve and raises the water temperature.
6. Make sure the anti-scald button is set correctly before you tighten anything.
7. Retighten the set screw with the Allen wrench and replace the set screw cover.

The video demonstrates the change toward hotter water. Ella's temperature guide states that the valve arrives set at 100.4 F and can be adjusted downward, and the same handle, collar and set screw are the parts involved in a cooler setting. Whichever direction you move it, the handle position is only the preset. The water at the spout is the proof, so run the tub and check it with a bath thermometer before anyone bathes. If you would rather not work on the valve yourself, a local licensed plumber can do this in the same visit as any other faucet service, and Ella does not send technicians.

Check the Result Against the Published Ceiling

Ella's owner manuals carry one water temperature ceiling for walk-in tub bathing: 100.4 F. The manuals state that water in excess of 100.4 F may be harmful to your health, that prolonged immersion can lead to hyperthermia, and that bathers with heart conditions, those taking medication and anyone who is pregnant should consult a physician. That is why the factory preset sits at 100.4 F and why setting the limit stop above it is not recommended. Walk-In Tub Water Temperature by Condition: A Reference Table (Not Medical Advice) gathers the published guidance below that ceiling. A bath thermometer in the tub water is the final check and, for a bather with reduced sensation, the only reliable one.

When the Limit Stop Is Not the Problem

If the handle is at the factory position but the water still runs hotter than the setting, the limit stop is not what needs adjusting. The usual cause is a cartridge fouled by calcium, iron or other heavy particles in the water, so it no longer holds its setting. Why Is the Water in My Walk-In Tub Too Hot? walks through the checks in order: confirm from your order that a TCV is present, note the setting, measure the water at the spout, and if it is well above the setting have a licensed and insured plumber remove and clean or replace the cartridge. The same fouling can block the hot side instead, which shows up as cool water at the tub while the sinks run hot, covered in Why Is There No Hot Water at the Tub When the Sinks Have Hot Water?, or as a fill that has slowed to a trickle because scale is choking the intake screens.

The second video on this page shows the cartridge service. With the water supply shut off, the handle comes off by loosening the Allen bolt, then the cover plate, the TCV governor, the washers and the escutcheon plate. The metal collar is loosened with channel locks or vice grips on the unthreaded flat wrench area so the threads are not damaged, the cartridge unscrews, and the intake screens and the bottom of the cartridge are cleaned with a soft brush and CLR. The gaskets are lightly lubricated with lithium grease before the cartridge and collar go back, tightened securely but not over torqued. Ella recommends this removal and cleaning be done only by a licensed, insured contractor or plumber.

Two warranty points matter here. The TCV carries a 1-year limited warranty, separate from the Lifetime Limited parts warranty on the rest of the tub, and cartridge sticking caused by calcium, iron or other heavy particles in the water is not covered. That is why an inline filter or mesh on the supply lines is required and must be cleaned periodically. If the valve still overshoots after the cartridge has been cleaned, or you need documentation on the valve for an inspector, open a ticket at ellasbubbles.com/support or call (800) 480-6850 with a photo of the faucet and valve, the measured water temperature, the setting you selected and your order details.

Related Guides

• Temperature Control Valve (TCV) Stuck or Not Mixing: Cleaning the Cartridge and Replacing the Valve
• Replacing a Failed Thermostatic Control Valve: Cleaning First, Cartridge Versus Whole Valve, and How to Order
• 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

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