Which Ella walk-in tub keeps the bath water hot at a set temperature?

Any Ella walk-in tub ordered with a hydro massage package keeps the bath water hot, because every hydro package includes an in-line water heater that holds your fill temperature for as long as the hydro pump runs. The set temperature itself comes from a different part: a tub ordered with an Ella thermostatic faucet package fills through a Thermostatic Control Valve that blends hot and cold to a fixed setting before the water reaches the spout. What Is an In-Line Water Heater on a Walk-In Tub? covers the heater on its own, and this page puts the two parts together so you can choose a configuration that fills at a set temperature and then stays there.

Two Parts, Two Different Jobs

People searching for a walk-in tub that keeps the water hot often picture a thermostat on the tub, the way a hot tub works. Ella tubs do not work that way, and knowing the split saves disappointment later.

• The Thermostatic Control Valve, or TCV, is a deck-mounted anti-scald valve that sits beside the faucet with its own control handle and governor. Hot and cold supply lines feed into it, a cartridge inside mixes them to the temperature you have set, and the valve comes factory set at 100.4 degrees Fahrenheit. 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 consistent through the whole fill. That matters more in a walk-in tub than in a shower, because you cannot step out of the way of a temperature spike until the tub drains.
• The in-line water heater is plumbed into the hydro massage loop under the tub. Once the water is 2 inches above the highest jets and you switch on the hydro massage, the pump pulls water through the heater and back out through the jets, and the heater offsets the natural cooling of the bath. It switches on and off with the pump, so there is no heater button and no thermostat to set. It does nothing for the air massage, which has no heater.

Put simply, the TCV sets the temperature and the heater holds it. Neither part raises the temperature of a bath that was filled too cool, and the heater does nothing while the hydro pump is off. The short in-line heater video shows this in practice: you set a comfortable temperature at the five-piece or two-piece fast-fill faucet, and when you engage the hydro massage, the heater working with the water pump maintains that warmth so you stay comfortable through the soak.

Which Configurations Include the Heater

The heater comes with the therapy package, not with a particular model. Every Ella tub with a hydro massage package has one, across the Standard and Zen family, the stainless-door tubs, the Ultra, the outward-swing tubs, the two-seat tubs, the Transfer tubs and the LayDown hydro option. Air-only and soaking tubs have no hydro pump and no heater, and the heater cannot be added to those configurations. The table gathers the figures printed on the spec sheets and in Ella's published guidance. Where a rating does not appear in the sources for this page, the cell says not listed.

From the bather's seat, every hydro configuration behaves the same way. The rating tells you how much cooling the heater can offset, not whether it can warm the bath up, so a higher wattage is not a reason to expect hotter water. The one placement difference that changes how you use the tub is on Hydro plus Independent Foot Massage builds, where the heater is attached to the foot massage pump. On those tubs, running the foot jets is what keeps the water warm, and the seat jets alone will not do it. If a fixed fill temperature matters to you, the thermostatic faucet package is the part to ask for, because the dual-lever 5-piece fast-fill faucet and the 2-piece fast-fill faucet are not thermostatic and are set by hand at the levers.

Which Models Offer the Thermostatic Faucet Package

The TCV comes with the thermostatic faucet package rather than with a tub, so two tubs of the same model can differ. Ella's safety guidance names the package as offered on the Elite, Petite, Royal, Deluxe and Companion, among others. The surest way to know what you have, or what you are ordering, is the order confirmation. On an installed tub, look on the deck for a separate temperature handle beside the faucet. What Is a Thermostatic Control Valve (TCV) on a Walk-In Tub? has the full description of the valve.

The TCV adjustment video shows how the set point works. Under the handle is a spring-loaded locking pin, which is the anti-scald mechanism, and a button that springs back when the valve is set at 100.4 degrees. Raising the setting involves removing the set screw cover, loosening the set screw with an Allen wrench, lifting the handle off the brass fitting and reseating it a quarter turn counterclockwise, then confirming the anti-scald button is set correctly before retightening. Ella's manuals warn that water above 100.4 degrees Fahrenheit may be harmful, so treat the factory setting as a ceiling rather than a starting point.

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. That may reduce flow and lengthen the fill. Why Is the Water in My Walk-In Tub Too Hot? walks through that choice and the checks that come before it.

Your Home Water Heater Still Sets the Starting Point

Because the in-line heater only maintains temperature, a hot bath begins with a hot fill, and that depends on the water heater in your house. Ella's guidance is a tank of 75 gallons for most models, 80 gallons for the two-seat Tub4Two and Companion, and 100 gallons for the Big4One, Shak, Big4Two and Escape, which may also call for a dedicated heater. A 40-gallon tank is not recommended, because it works only if nothing else draws hot water during the fill. With a tankless unit the limit is flow rather than storage. The recommendation is a unit rated for at least 11 gallons per minute, and the support team's own example of a 27 kW unit rated at 4.8 gallons per minute struggles to keep up with the fast-fill faucet, so the whole fill arrives cooler than you set. Does a tankless water heater work with an Ella walk-in tub? explains how to tell the two shortfalls apart.

What to Expect Once the Tub Is Installed

Water that cools while you soak with the hydro off is expected, because the heater is not running. Water that cools while the hydro is running points to something to check: whether the tub actually has a hydro package, whether the heater cord is plugged into the correct port on the control box, and on Hydro plus Hydro Foot builds, whether the foot pump is running. Why Doesn't the Water Stay Hot and Why Do the Jets Blow Cold? lists those checks in order.

On warranty, the two parts are treated differently. The in-line heater is covered as supporting equipment under the Lifetime Limited Warranty. The TCV carries a 1-year limited warranty, and cartridge sticking caused by calcium, iron or other heavy particles in the water is not covered, which is why an inline filter or mesh on the supply lines is required and must be cleaned periodically. Cartridge removal and cleaning should only be done by a licensed, insured plumber. If you need help confirming which parts your tub has, open a ticket at ellasbubbles.com/support or call your Ella dealer or the team at (800) 480-6850 with your model and serial number.

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

Related Guides

• How Do I Adjust the Maximum Temperature on a Walk-In Tub Thermostatic Valve?
• Temperature Control Valve (TCV) Stuck or Not Mixing: Cleaning the Cartridge and Replacing the Valve

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