How Do I Adjust the Maximum Temperature on a Walk-In Tub Thermostatic Valve?

The Thermostatic Control Valve, or TCV, on an Ella walk-in tub leaves the factory set at 100.4 degrees Fahrenheit, and the handle on the deck turns down from that point whenever you want a cooler bath. Raising the maximum above the factory setting is an internal adjustment: the set screw cover comes off, the set screw is loosened with an Allen wrench, and the handle is reseated a quarter turn counterclockwise on the brass fitting so the valve passes more hot water. Ella's owner manuals name 100.4 F as the temperature above which bathing water may be harmful, so turning the valve up is not recommended, and the background on the valve is in The Thermostatic Control Valve (Anti-Scald): Which Faucets Have It, Its Setting, and Water-Heater Advice.

First, Confirm Your Tub Has a Thermostatic Valve

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. Look on the deck for a separate temperature handle with its own governor beside the faucet. If it is there, you have a TCV. If your tub was ordered with the dual-lever 5-piece fast-fill faucet, the red handle is hot, the blue handle is cold and the middle lever is the diverter for the hand shower; there is no thermostatic valve, and the maximum temperature is simply whatever you set by hand. The 2-piece fast-fill faucet, with a single lever that swings left for hot and right for cold and a diverter button under the spout, is not thermostatic either. What Is a Thermostatic Control Valve (TCV) on a Walk-In Tub? explains what the valve does and which models it is offered on. If your configuration has no TCV and you want a fixed ceiling, a qualified contractor can add an external temperature control valve on the hot water line, though that may reduce flow and lengthen the fill.

What the Anti-Scald Button Does

Inside the TCV handle is a spring-loaded locking pin. This pin is the anti-scald mechanism, and it sets against a locking collar. Turning the handle toward cooler water needs nothing but the handle. Turning it toward warmer water requires pushing the button, and the button springs back into place when the handle reaches the 100.4 F setting. That is the everyday behavior: you can lower the temperature freely, and you cannot drift past the factory maximum without deliberately pressing the button and, beyond that, without resetting the handle as described below. The valve holds the blend steady in both directions. If the cold supply drops, it limits the hot flow, and if the hot supply drops, it limits the cold, which matters in a tub you cannot step out of until it drains.

Turning the Setting Down for Comfort

Lowering the maximum is the adjustment Ella recommends, and it needs no tools. Turn the temperature handle toward cooler water until the fill feels right, then confirm with a bath thermometer in the tub water, which is the only reliable check for a bather with reduced sensation. Ella's published guidance points to cooler settings for many purposes. Warm water between 92 and 100 F is the published range for sore joints and muscles, and warm rather than hot water is the guidance for dry or sensitive skin, with red skin afterward a sign the water was too hot. The full list by situation, with who decides in each case, is in Walk-In Tub Water Temperature by Condition: A Reference Table (Not Medical Advice). Bathers with heart conditions, anyone taking medication and anyone who is pregnant should consult a physician before warm-water bathing, and prolonged immersion can lead to hyperthermia at any setting.

Resetting the Internal Stop for Hotter Water

Ella's TCV adjustment video shows the internal reset step by step on the valve handle, and the steps below follow it. Read the whole sequence first, and keep in mind that the factory setting is the safe bathing ceiling in Ella's manuals. If you are not comfortable working on the valve, a local licensed plumber can do it.

1. Remove the set screw cover and loosen the set screw with an Allen wrench.
2. Place the handle on top of the brass fitting and turn it toward warmer water.
3. Briefly take the handle off the brass fitting, then reset it, turning the handle a quarter turn counterclockwise. This allows more hot water to flow through the valve and raises the water temperature.
4. Make sure the anti-scald button is set correctly against the locking collar.
5. Retighten the set screw with the Allen wrench and replace the set screw cover.

After the reset, fill the tub and measure the water at the spout with a bath thermometer before anyone bathes, then check it again in the tub. Ella's manuals ask every bather to check and adjust the water temperature before use, whatever valve is fitted. Keep in mind that the TCV is one layer of scald protection and the water heater is another. The Consumer Product Safety Commission recommends a 120 F water heater setting to reduce tap-water scald risk, and model plumbing codes limit the hot water supplied to bathtubs to 120 F through a device conforming to ASSE 1070. Your local plumbing inspector decides which code applies, and the references are laid out in Anti-Scald and Thermostatic Valve Standards for Walk-In Tubs: ASSE 1016, 1070 and the Ella TCV.

If the Water Runs Hotter Than the Setting

A valve that delivers water well above where the handle is set has not lost its adjustment. The usual cause is a cartridge fouled by calcium, iron or other heavy particles in the water, so it no longer holds its setting. Note the setting, measure the water at the spout, and have a licensed and insured plumber remove and clean or replace the cartridge. The TCV carries a 1-year limited warranty, separate from the lifetime limited parts warranty on the rest of the tub, and cartridge fouling from contaminated water is not covered. That is why an inline filter or mesh on the supply lines is required and must be cleaned periodically. The step-by-step checks are in Why Is the Water in My Walk-In Tub Too Hot?. 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 your Ella dealer or the team at (800) 480-6850 with a photo of the faucet and valve, the measured water temperature, the setting you selected and your order details.

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

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
• Tub Fills Only Scalding or Only Cold and Will Not Mix to Warm

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