Can the Supply Lines Run Under the Tub Frame to Existing Plumbing?

Yes. An Ella walk-in tub stands on adjustable leveling legs with about 3 inches of clear space beneath it, so the hot and cold supply lines and the 2 inch PVC drain line can be routed under the tub to your existing house plumbing, including a plumbing wall or house drain at the opposite end from the faucet. The hoses themselves are described in What Are the Supply Lines on a Walk-In Tub Faucet?, and this page covers how your plumber uses that space, where the shut-off valves need to end up, and the one connection that can never be closed off.

What Is Under the Tub When It Arrives

Three things make under-frame routing practical. The tub sits on adjustable leveling legs rather than flat on the floor, which leaves roughly 3 inches of clearance between the floor and the underside of the shell. The back of the tub is open, so the frame does not box in the plumbing. And the faucet connections are flexible braided hoses rather than rigid pipe, so they can follow whichever path your plumber chooses.

• Supply lines: two 3/4 inch by 5 foot braided stainless steel hoses ship with every Ella 2-piece and 5-piece fast-fill faucet set, one for hot and one for cold. A third line under the deck feeds the spout, and the hand shower rides on its own 5 foot braided hose with a back-flow prevention valve.
• Where to find them: the lines are individually wrapped, boxed and placed inside the tub or under the frame before the tub is crated. If a line seems to be missing, look in both places before reporting it, and keep all packaging material.
• What is not in the crate: shut-off valves and PVC drain fittings are not included with the tub. Your plumber supplies both.

Because the hoses are a fixed 5 foot length, the plan for where the shut-off valves sit is really a plan for where the hoses end. That is the detail to settle before the tub is moved into the alcove.

Running the Lines to Plumbing at the Other End

The common version of this question comes from a remodel where the old tub's valves sat on one wall and the new walk-in tub's deck faucet lands at the other end. You do not have to move the plumbing wall. With the tub up on its legs, the hot and cold lines and the drain line can run under the tub to the existing connections, and the old valve location is simply capped. It also helps to know where the drains will be before the tub arrives: the door and the drains are on opposite sides of an Ella walk-in tub, so a right-side door tub has its drains on the left and a left-side door tub has its drains on the right, as you face the tub.

1. Dry-fit the tub and mark its final position, including which end the faucet deck faces and which side the door and drains sit on.
2. Have your plumber make the hot, cold and drain connections at the back of the tub while it is pulled out, since the open back gives access before the tub is pushed into place.
3. Route the lines under the frame to the house plumbing, keeping them clear of the leveling legs and anything that could pinch or kink a hose.
4. Push the tub into its final position, level it on the legs, and confirm nothing under the tub is trapped or bent.

One rule is not negotiable. Ella walk-in tubs have two oversized 2 inch drains, and both must stay connected to the house drain. Neither drain can be blocked off to simplify the run, so the drain plan has to carry both to the house connection before the supply lines are finalized. Where the plumbing ends up on an exposed end of the tub, the reversible end panel that ships with the tub covers the plumbing and the frame on that side, and a second panel is available when the tub sits against a wall with both ends exposed.

Where the Shut-Off Valves Belong

Ella's video on hot water supply, shown on this page, recommends 3/4 inch supply lines with easily accessible shut-off valves and reminds you that 5 foot supply lines are included with every Ella 2-piece or 5-piece fast-fill faucet set. Accessible is the important word. Routing the lines under the tub is fine. Burying the shut-off valves under the tub is not. Set the valves where they stay reachable through the front apron access panels, so the faucet can be isolated for a cartridge change or a leak without pulling the tub away from the wall.

That placement pays off on day one as well. When a new tub fills slowly, the first thing to check is whether both shut-off valves are fully open, because a partly open valve is the most common and easiest fix, as Why Does My Walk-In Tub Fill So Slowly? explains. A valve you can reach through the apron is a valve you can check in a minute, and a valve you can close is what protects the bathroom if a hose ever needs replacing.

Does the Under-Frame Run Change the Line Size?

No. The faucet end of the system is always 3/4 inch on current sets, and the house side is whatever your home delivers to the shut-off valves. Ella recommends 3/4 inch house lines, and the 2-piece set is designed for 16 GPM at 60 PSI while the 5-piece set is designed for 18 GPM at 60 PSI with ideal plumbing. Existing 1/2 inch house lines will work, and the tub simply fills more slowly. Do I need 3/4 inch supply lines for the Ella fast-fill faucet? walks through that decision in detail.

• If the existing plumbing is 1/2 inch, the included 3/4 inch hoses connect through a 3/4 inch to 1/2 inch reducer, a standard plumbing part.
• If you are opening the floor or wall anyway to make the run, that is the moment to bring 3/4 inch lines to the valves.
• In real homes a fill runs about 7 to 15 minutes depending on tub size and your water supply, whichever path the lines take. The GPM figures describe what the faucet can pass, not what every home will see.

The faucet sets themselves, the 2-piece single-lever set and the 5-piece set with separate hot and cold handles, are described in What Is a Fast-Fill Faucet on a Walk-In Tub?.

What to Settle Before Your Plumber Starts

• Which end the faucet deck is on, and where the existing hot, cold and drain connections are in relation to it.
• Where the two shut-off valves will sit so they stay reachable through the front apron access panels after the tub is in place.
• How both 2 inch drains reach the house drain, since neither can be capped.
• Whether the house lines are 3/4 inch or 1/2 inch, and whether a reducer is needed at the valves.
• The hot water supply. Ella's video recommends the maximum capacity water heater available for the house, and anything less than 75 gallons is not recommended.

Ella does not send technicians, so the connections are made by your local licensed plumber. Your Ella dealer or the team at (800) 480-6850 and ellasbubbles.com/support can confirm the plan against your specific model and floor layout before anything is cut.

Watch: Ella's Bubbles: Determining Correct Hot Water Supply For A Walk-In Tub with chapters and a full transcript.

Related Guides

• Plumbing and drain configurations: connecting your walk-in tub to the house drain
• What Size Water Heater Do I Need for My Walk-in Tub?
• Electrical requirements by model: dedicated GFCI circuits for your walk-in tub

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