Do I need to glue the drain caps if only using two drains?

Yes. Any drain port you are not using should be capped with the white PVC caps that ship in the tub's parts box, and those caps are glued in place with PVC cement. Ella recommends the original PVC caps cemented on, and does not recommend a rubber cap. The caps close the open ports of the T-type drain body described in What Is a 4-Port T-Type Drain on a Walk-In Tub?, and whoever installs the tub does the capping.

Why There Are Ports to Cap in the First Place

Most Ella walk-in tubs use Dual Drain Technology: two 2 inch gravity drains, each dropping into a four-port T-type PVC body, for four 2 inch ports in total. The ports exist so the house drain can leave in whichever direction your plumbing needs, from either side of the tub. Connecting all four ports to the house main gives the fastest possible drainage. Connecting two ports on the convenient side is the most common build, and even one port still works. Whatever is not connected is open pipe under a tub full of water, which is why it has to be closed. The number of caps depends on the model:

• Dual Drain models, which cover the stainless-door, Ultra, outward-swing (except the Front Entry), two-seat and Transfer families, have two floor drains, each on its own T-type body, and ship with two end caps.
• The Standard, Standard60, Zen, Zen60 and Flow have one 2 inch drain on a T-type body with two connectable ports and ship with one end cap for the unused side.
• The Front Entry uses a single 2 inch 2-port drain, and the LayDown tubs use a threaded brass drain with a supplied elbow rather than a PVC T-type body, so the PVC cap question does not arise there.

Finding the Caps and Counting Them

The caps are packed in the parts box inside the tub or under the frame, and every small part is individually wrapped, boxed and packed there. Before your installer starts, count the end caps: two for a dual-drain tub, one for the Standard family. The two-seat spec sheets print it the same way, two 2 inch 4-port PVC drains with two end caps included, and Installing the Two-Seat Family, Part 2: Drains, Dual Spout Faucet, Three Dedicated Lines, Grab Bar, Door Check and Walls shows where the drains fall in that family's installation sequence. If a cap seems missing, look inside the tub and under the frame first before reporting it, because a small wrapped part is easy to overlook in the crate.

How the Unused Ports Are Sealed

The method is ordinary PVC plumbing practice. The original white PVC cap goes onto the unused port and is glued with PVC cement, the same way the connected ports are joined to the house drain with standard PVC fittings, so the cap stays sealed for the life of the installation. Ella does not recommend a rubber cap. The installation video on this page shows the dual 2 inch drains with four ports, the house drain connected to either side, and the unused ports capped off. Whoever installs the tub caps the unused ports. Ella does not send technicians, so this is your licensed plumber's work, and technical support can answer the plumber's questions. After installation, make sure every unused port is capped and every joint is snug.

Deciding Which Ports to Use

Choosing which two ports to cap is really choosing which side the house drain leaves from, and a few rules make the choice easy:

• The T-type bodies accept standard PVC fittings, and the installer joins them to a 1.5 inch or, ideally, a 2 inch house drain with a T or a Y connector. A Y adds fewer sharp turns, which is why Ella prefers it, and fewer turns means less resistance and faster draining.
• On a dual-drain tub the two drains join under the tub into a single house connection, so you need one P trap and one reducing fitting, not two drain pipes in the slab.
• If the house drain is on the far side or in the center, there is roughly 3 inches of clearance under the tub for 2 inch PVC, so the run can go to either side.
• If the house line is 1.5 inches, a 2 inch to 1.5 inch reducing coupling on the tub side of the P trap riser, or a 2 inch PVC 90 off the drain body reduced ahead of the P trap, steps it down. My House Drain Is 1.5 Inches. Will the 2 Inch Tub Drain Work? and Connecting the 2 Inch Tub Drain to 1.5 Inch House Plumbing, and the Straight-Down Exit for the LayDown Brass Drain show the layouts.
• The PVC pipe from the tub to the house drain is not included, and the house drain should be tested for free flow before the tub goes in, because a dual drain cannot fix a slow house line.

Even with a single drain connected to a 2 inch floor drain, the tub still empties in about two minutes, so a two-port connection with the other two ports cemented shut is a normal, well-performing installation rather than a compromise.

If You Want to Pull the Tub Later

The T body directly under the tub is where Ella's drain ends and your plumber's work to the sewer begins, so everything past that point is ordinary PVC from any plumbing supply house. If you want to be able to remove the tub later without cutting pipe, a flexible P trap or a no-hub coupling at that joint is a sensible choice. The cemented caps on the unused ports stay with the tub either way, and nothing about them needs to come apart for service.

Watch: Walk-In Tub Installation Guide & Tips, Easy Process | Ella’s Bubbles with chapters and a full transcript.

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