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How Do Walk-In Tubs Work, From the Door Seal to the Drain?

Updated September 2026

▶Glossary7
  1. The Door, the Latch and the Seal
  2. Filling the Tub
  3. Draining the Tub
  4. Showering Behind the Door
  5. Related Guides
  6. Related Videos
  7. Common Questions

A walk-in tub works like a conventional bathtub with a watertight door built into its side. You step through the door, close and latch it so the door seal holds the water in, fill the tub from the faucet, and when you are done the tub empties by gravity through 2-inch floor drains before you open the door and step out. On an Ella walk-in tub no pump is involved in draining, and a tub connected to a proper 2-inch drain line typically empties in two minutes or less, as explained in Drainage and Fill Time.

The Door, the Latch and the Seal

The door is what sets a walk-in tub apart. Ella builds both inward-swing and outward-swing doors. The Standard, Zen and Zen60 use an inward-swing acrylic S-shape door. The Capri, Monaco, Front Entry, Mobile, Lounger, ShaK, Big4One and Tub4Two use an outward-swing U-shape door made of PVC composite and tempered glass, and Ella also offers an extra-wide outward-swing L-shape door.

Outward-swing doors lock with a gear-and-shaft mechanism. The U-shape door uses a three-shaft gear and lock system, and the L-shape door uses a two-shaft system. When you turn the handle, the gears drive the latch pins into openings in the striker plate on the door frame, and the door seal is what keeps bath water inside the tub while you bathe. The video below shows the gear-and-shaft lock on the outswing doors and how easily the handle engages and disengages.

One detail surprises many new owners. The pin openings in the striker plate are not sealed underneath, so a little water that clings to the door and the track can drip through after a bath. This is not a leak from the tub shell, and no part is missing. Water Drips Through the Striker Plate Pin Hole: Is a Part Missing? explains how a licensed plumber can add a small catch and hose if the drip bothers you.

Filling the Tub

The faucet on an Ella tub is capable of a fill rate of about 16 gallons per minute. For a tub with a capacity of around 60 gallons, that fill rate means the tub fills quickly rather than requiring a long wait before you can begin bathing. Tubs ordered with an Ella faucet package also include a built-in extendable multi-function hand shower, so the same tub works as a seated shower.

Draining the Tub

Ella tubs drain by gravity. Water flows straight down through 2-inch floor drain openings and out to the house drain line, and most models carry two independent 2-inch drains with an overflow. Because the tub does not rely on a pump to drain, a tub connected to a proper 2-inch drain line typically empties in two minutes or less.

Older installation manuals also show a small secondary door drain near the door. That line relied on a check valve that could stick and push water back toward the door as the tub emptied, which looked like a door leak even when the seal was fine, so Ella eliminated it. Current tubs ship with a short capped stub in its place, and the stub stays capped and unconnected. Why the Door Drain on My Walk-In Tub Is Capped and Should Stay That Way covers what your installer should do with it.

Showering Behind the Door

Because the door and seat sit on the open front of a three-wall alcove, Ella offers a 4-fold tempered glass shower screen for seated walk-in tubs. It closes off the front of the alcove while you shower and folds back out of the way so the door stays clear for entry. Which Glass Shower Screen Fits Your Ella Tub and Where It Mounts explains which screen goes with which tub.

Watch: Benefits of Outward Door Swing Walk-In Tubs | Ella's Bubbles with chapters and a full transcript.

Chapters in this video
  1. 0:00 Outward Swing Door Design The video introduces the robust vault-like design of Ella's Bubbles outward swing walk-in tub doors, featuring oversized tapered pins for a secure seal.
  2. 1:26 Easy Door Operation The video demonstrates how easy it is to close and operate the outward swing door, highlighting the tapered pins that do all the work.
  3. 2:01 Accessibility and Peace of Mind The door is designed for ease of use, even with limited mobility, providing maximum peace of mind that the seal will never leak.
Chapters in this video
  1. 0:00 Outward Swing Door Types We show the two types of outward swing doors on Ella's Bubbles walk-in tubs: the U-shaped and L-shaped doors.
  2. 0:20 Installing the Handle We demonstrate how to properly align the tabs and place the handle onto the latch mechanism.
  3. 0:48 Correct Handle Orientation We illustrate the correct handle orientation when the door is unlocked and locked, and show incorrect installations.
Chapters in this video
  1. 0:00 Ella's Dual Drain Technology Ella's Bubbles walk-in tubs feature exclusive dual drain technology with oversized two-inch drains for efficient water removal.
  2. 0:17 How Dual Drains Work The video explains how Ella's dual two-inch drains connect to a house drain, offering maximum draining capacity.
  3. 0:47 Connecting to Your House Drain The video demonstrates connecting the tub's dual four-port t-type drains to a house drain on either the left or right side.
  4. 1:14 Dual Air Vents and Gravity Easy-turn drain handles double as air vents, eliminating air pockets and maximizing water outflow through a gravity-driven system.

Common Questions

Does a walk-in tub use a pump to drain the water?
No, Ella walk-in tubs drain by gravity rather than a pump. Water flows straight down through the 2-inch drain openings and out to the house drain line. When the tub is connected to a proper 2-inch drain line, it typically empties in two minutes or less.
How does the outward-swing door on an Ella tub lock shut?
Outward-swing doors use a gear-and-shaft locking mechanism. The U-shape door has a three-shaft gear and lock system and the extra-wide L-shape door has a two-shaft system. Turning the handle drives the latch pins into the striker plate on the frame, and the door seal keeps the water inside while you bathe.
Is it normal for a few drops to come through the striker plate?
Yes, a small amount of water can pass through the pin openings in the striker plate after a bath. Those openings are not sealed underneath, so water that collects in the door track can drip to the floor beneath the tub. No part is missing, and a licensed plumber can fit a small catch and hose if you want that water routed to the drain.
Why is there a capped tube near the door of my tub?
That is the stub of the former door drain line, which Ella eliminated because its check valve could stick and push water back toward the door while the tub emptied. Leave the cap in place and do not connect the stub to anything. The tub drains through the main floor drain and overflow instead.
How quickly does an Ella walk-in tub fill and drain?
The faucet is capable of a fill rate of about 16 gallons per minute, so a tub with a capacity of around 60 gallons fills quickly. Draining is gravity driven and typically finishes in two minutes or less on a proper 2-inch drain line. Actual times depend on your home's water supply and drain piping.

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