What Is Dual Drain Technology on a Walk-In Tub?
Updated September 2026
Dual Drain Technology is Ella's gravity-driven drain system that pairs two oversized 2 inch floor drains, each on its own 4-port T-type drain body, so an average-size Ella walk-in tub empties in about 80 seconds under ideal house-drain conditions. Because you sit in the tub until it empties, drain speed is a comfort feature.
How It Works
The industry-standard bathtub drain is a single 1.5 inch opening. Most Ella walk-in tubs instead use two independent 2 inch drains, each with its own deck opener. Under the tub, each drain ends in a T-type PVC body with 2 inch ports, so your installer can connect the house drain on the left, on the right, or to all four ports for maximum flow, capping unused ports with the included end caps. A Y fitting beats a T because fewer sharp turns move water faster, and a 2 inch house drain is recommended where possible.
The system is purely gravity driven, so a power outage or pump fault can never leave a bather waiting in a full tub. A field test in Ella's product video recorded complete drainage in 52 seconds, while the Big4Two video mentions about 3 minutes 30 seconds for that 145 gallon two-seat tub. Your own time depends on your model's capacity, how many ports are connected, and your house drain. Read more in How Fast Does a Walk-In Tub Drain and Plumbing and Drain Configurations.
Which Ella Models Have It
Standard on the stainless-door, Ultra, outward-swing (except the Front Entry), two-seat and Transfer families:
Not every Ella tub uses it. The Standard, Standard60, Zen, Zen60 and Flow have one 2 inch gravity drain with an emergency pull-up chain (Model profile), the Front Entry has a single 2 inch 2-port drain, and the LayDown tubs use a single brass drain.
What to Know as an Owner
Open both drain handles completely for full speed, and close both completely to hold water. If the tub seems slow, have a plumber confirm the house drain flows freely; two drains cannot fix a restricted house line. Clear hair from the drain covers. The door and the drains sit on opposite sides of the tub, so a right-side door means left-side drains. For a ticket at ellasbubbles.com/support, have your model, serial number, how many ports were connected, the fitting used, and whether one drain or both seem slow. See Tub Drains Slowly or Will Not Drain and Drain Cable Replacement and Adjustment for the first checks.
Related Guides
- Will a 3-Inch Sewer Line Make My Walk-In Tub Drain Slower Than a 4-Inch Line?
- Connecting the Dual Drains in a Tight Space and What the Drain Package Includes
- Draining to a Washing Machine Box or a Drain Higher Than the Tub: Why Gravity Drains Need a Pump
- How does the Ella Elite drain work and how fast does it empty?
Common Questions
How fast does an Ella walk-in tub drain?
Does the walk-in tub drain need a pump?
Do all four ports have to be connected to the house drain?
Does my Standard or Zen tub have Dual Drain Technology?
About this guide. Answers in the Ella’s Bubbles Support Center are compiled from real conversations with tub owners, our technicians’ notes and the product documentation, then reviewed by our team. Tub models and options have evolved over the years, so a detail here may differ slightly from your exact tub. If something looks different on yours, send us your serial number and a specialist will confirm it for your model.
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