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Lowering the Tub: Below-Subfloor Drains, 3 Inch Thresholds, and What It Does to the Warranty

Updated September 2026

▶Glossary7
  1. The Default Frame Height
  2. Recessing the Tub Below the Default Height
  3. The S-Class 3 Inch Threshold Models
  4. Models That May Not Be Lowered
  5. Planning Checklist for a Recessed Installation
  6. Related Guides
  7. Common Questions

Lowering a walk-in tub for a smaller step-in is possible on most Ella models, but it is a custom installation with a trade-off. Ella walk-in tubs leave the factory with the frame and threshold height preset so the drain piping passes under the tub and above the floor, which keeps the installation simple and keeps every part of the tub intact. The tub can be lowered by putting the drain below the subfloor and, on most models, cutting the bottom of the apron or end panel to clear the floor. The warranty does not cover the parts that are cut or altered. This article explains the default height, what a recessed installation involves, the 3 inch threshold models, and where the limits are.

The Default Frame Height

The adjustable leveling legs set the tub at a height that lets the 2 inch drain piping run beneath the tub, above the floor, to tap into your existing house drain. There is approximately 3 inches of clearance under the tub for that piping. This is why an Ella tub can go onto a concrete slab or an upper floor without opening the floor, and it is the installation the warranty and the manuals assume. Our article on slabs, condos, and upper floors covers those settings, and drain configurations and the house drain shows the routing options at the default height.

Recessing the Tub Below the Default Height

The leveling legs allow the tub to be lowered, but as the tub comes down, the apron, the end panel, and the drain assembly will hit the floor. To go lower, the installer cuts subfloor access for the drain so the piping drops below the subfloor, and cuts the bottom of the apron and, for corner installations, the end panel. The manuals advise using masking tape and appropriate tools to avoid damaging the acrylic. When the drain is installed below the subfloor, thresholds can be as low as 3.5 inches.

Warranty effect: this custom installation voids warranty coverage on the damaged or altered parts. The rest of the tub remains covered, but a cut apron or end panel is on you from that point forward. Please weigh the lower step-in against that trade-off with your installer before cutting anything, and never cut the shell or frame. The full list of installation choices that affect coverage is in installation choices that affect your warranty.

The S-Class 3 Inch Threshold Models

The S-Class Series: 3 inch vs 6 inch thresholds
Chapters in this video
  1. 0:00 S-Class Tub Features Ella's S-Class walk-in tubs feature a low threshold, textured floor, and a sturdy stainless steel frame.
  2. 0:46 Innovative Jetting Design Ella's walk-in tubs are known for their innovative jetting design, including hydro and air massage systems.
  3. 1:26 Faucet Sets and Safety Features Customers can choose from various fast-fill faucet sets, and the tubs include grab bars and a secure door latch for safety.
  4. 1:50 Optional Accessories for Comfort Ella's offers several accessories like a heated seat, glass screen, and support pillows for enhanced comfort.

Watch: Ella's S-Class Walk-In Tubs with Easy Entry & Textured Floor for Seniors with chapters and a full transcript.

The S-Class series was offered with either a 3 inch low threshold or a 6 inch standard threshold, and the video explains the difference. On the 3 inch threshold tub, the frame is lowered to the floor and the jets are raised off the floor to accommodate the low step-in; on the 6 inch threshold tub, the frame is raised to fit the drain beneath. Because the 3 inch frame sits on the floor, the 3 inch height requires subfloor access to the drains, so it is not a slab-friendly configuration without cutting the floor. Adjustable leveling legs remain crucial for proper door alignment on both versions. If you have an S-Class unit, contact support with your serial number before planning any change to its height, and see our S-Class legacy tubs article for parts and support on that series.

Side-view CAD diagram of the Ella S-Class 30x52 walk-in tub showing the interior depth and threshold dimensions
Side elevation of the S-Class 30x52. The threshold height depends on whether the frame sits on the floor or is raised for the drain.

Models That May Not Be Lowered

On the Petite, the end panel is a fixed height, so lowering the tub may not be possible on that model; please check with our team before planning on it. Tubs with jets on the floor also lose some clearance when lowered, which is why the low-threshold designs raise the jets instead. If a lower step-in is the goal, compare thresholds by model first; our step-in threshold heights by model article lists them, and for some bathers a model with a lower factory threshold or the wide L-shape door of the Transfer family can be a better answer than a recessed installation. A low-threshold shower is another option worth comparing; see walk-in tub versus low-threshold shower.

Planning Checklist for a Recessed Installation

  1. Confirm the house drain can be reached below the subfloor and that opening the floor is permitted in your building.
  2. Have the installer measure how far the tub must drop and exactly which panels need trimming, and mark cuts with masking tape.
  3. Level the tub with every leg touching and supporting equal weight at the new height, since misleveling is the number one cause of door leaks.
  4. Complete the pre-installation water test before the floor and walls are closed.
  5. Keep the trimmed panels removable so service access stays intact.
Senior woman stepping over the low threshold of an Ella Lounger walk-in tub through the open outward-swing door
The factory threshold is designed to be stepped over with a grab bar in hand. Compare model thresholds before planning a recess.

Common Questions

Can the tub be recessed to lower the step-in?
Yes, most Ella walk-in tubs can be recessed to lower the step-in by installing the drain piping below the subfloor. This custom installation also requires cutting the bottom of the apron and, for corner installations, the end panel to clear the floor. Please note that the warranty does not cover the parts that are cut or altered during this process.
Does the 3 inch S-Class need subfloor access?
Yes, the S-Class walk-in tubs with a 3-inch low threshold require subfloor access for the drains. This is because the frame on the 3-inch threshold S-Class model sits directly on the floor, necessitating the drain piping to drop below the subfloor. This configuration is not suitable for concrete slabs or upper floors without opening the floor.
Can I cut the apron or end panel to lower it?
You can cut the bottom of the apron or end panel to lower your Ella walk-in tub, and the manuals provide guidance on how to do this using masking tape and appropriate tools. However, it is important to understand that the warranty will not cover these specific parts once they have been cut or altered. The rest of the tub remains covered, but a cut apron or end panel will be your responsibility from that point forward.
Can the Petite be lowered?
Lowering the Petite walk-in tub may not be possible because its end panel is a fixed height. Before planning a recessed installation for a Petite model, please contact our team to confirm if it can be lowered. We recommend comparing step-in threshold heights by model first, as a different model with a lower factory threshold might be a better solution.
How low can the threshold go?
When the drain is installed below the subfloor, the threshold of most Ella walk-in tubs can be as low as 3.5 inches. For the S-Class series, a specific low-threshold configuration was offered with a 3-inch threshold, which also requires subfloor access for the drains. This 3-inch S-Class model has its frame lowered to the floor and jets raised to accommodate the low step-in.
Can the leveling legs be raised instead to gain drain clearance?
No, the adjustable leveling legs cannot be raised to gain additional drain clearance beyond the factory height. Each leg has a shorter screw that acts as a limit screw, preventing the legs from extending higher. The factory height already provides approximately 3 inches of clearance under the tub for the 2-inch drain piping to run above the floor.
Can the tub be sunk into the floor completely?
No, an Ella walk-in tub cannot be sunk into the floor completely as a supported installation. The tub's frame must remain accessible, and the apron and end panels must stay removable to allow for service access. Additionally, the shell or frame of the tub should never be cut. If you are considering any sunken design, please discuss it with our team before ordering.
Which tub has the lowest factory threshold?
The walk-in tub with the lowest factory threshold varies by model family. Our article on Step-In Threshold Heights by Model lists every current model and its threshold height, allowing you to compare options. This can help you decide if a recessed installation is truly necessary or if a model with a lower factory threshold, such as a Transfer family tub with a wide L-shape door, would better meet your needs.

Have a question that depends on your exact model or configuration? Open a ticket at ellasbubbles.com/support or call (800) 480-6850 and our technical support team will be glad to help you and your installer.

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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