A walk in tub installation comes down to four things: a level floor, a drain roughed in on the correct side, enough hot water to fill the tub, and the right GFCI circuit if the tub has jets or a heater. The manuals we opened expect licensed plumbers and electricians to make the hookups. For budgets, see our walk-in tub cost guide.
Walk in tub size: measure the space first
Measure your alcove wall to wall and from the back wall to the open edge, and check that the walls are square. Compare that to the tub’s outer dimensions, not its nominal name. The ANZZI 2853 spec sheet lists 52.5 x 28 x 40 inches overall, and the 2653 sheet lists 52.75 x 26.375 x 37.5 inches. Both note a plus or minus 0.5 inch variance and say to measure the tub on site before building any surround.
For a 60 inch alcove, ANZZI’s 53 to 60 inch listings include a 7 inch extension kit, and some Venzi listings include 3 side panels “for installation placement flexibility.” Our standard bathtub size guide explains how to measure an alcove.
ANZZI listings say delivery is curbside only, so check every doorway, turn and stair against the tub’s narrowest dimension. The walk-in tub manual linked from our ANZZI Coupe Premier listings says to move the tub by the frame handles, never the plumbing.
| Tub | Outer size (in) | Weight | Fill | Drain | Power |
|---|---|---|---|---|---|
| ANZZI Coupe Premier 28 in soaker, $3,264 | 52.5 x 28 x 40 | 120 lbs | 70 to 80 gal* | Left | None |
| ANZZI Coupe Premier air jetted, $4,326 | 52.5 x 28 x 40 | 155 lbs | 70 to 80 gal* | Left | 1 x 15 amp GFCI |
| ANZZI 53 to 60 x 26 air and whirlpool, $3,495 | 52.75 x 26.375 x 37.5 | 150 lbs | 50 to 60 gal* | Left | 1 x 20 amp GFCI |
| Venzi Artisan 26 x 53 soaker, $2,825.40 | 53 x 27 x 38 | 146 lbs | 55 gal | Right | None |
| Venzi 30 x 54 soaker, $3,084.30 | 54 x 30 x 37 | 153 lbs | 60 gal | Right | None |
| Venzi 32 x 38 soaker, $5,800 | 38 x 32 x 38 | 263 lbs | 45 gal | Left | None |
| Venzi 30 x 60 wheelchair accessible, $6,502.06 | 60 x 30 x 43 | 234 lbs | 45 gal | Right | None |
*ANZZI spec sheet figures, estimated with an occupant inside. Weights are empty. Venzi figures come from our listings.
Floor, framing and leveling
Add water and a bather to those empty weights and the floor carries far more. Our freestanding bathtub buying guide explains how water weight adds up.
The door seal depends on level. The manual says to check the floor with a 5 to 6 foot level and adjust the leveling feet until every foot touches. In its words, “a bad level will make your tub leak.”
Drain side and drain position
On ANZZI listings the drain and door sit on the same side. Pick the side that matches your existing drain so it does not have to move. The 2853 sheet puts the drain 11.5 inches from the side wall and 14 inches from the back wall; the 2653 sheet lists 8.5 and 14.5 inches.
Per the manual, the tub ships with a 1 1/2 inch waste and overflow, and auto drain models need at least a 1 1/2 inch sanitary drain in Schedule 40 pipe. A door drain hose with a check valve joins the main drain at about 45 degrees. A watertight waste and overflow is the installer’s responsibility.
Supply lines and faucet
ANZZI listings include a Quick Fill faucet with handheld shower. The Venzi 30 x 54, 32 x 38 and wheelchair accessible listings say the faucet is not included. The manual’s faucet diagram shows 3/4 inch hot and cold connections on 19 inch braided hoses; house supply lines are not included.
Walk in tub water heater sizing
The tubs above list fills of 45 to 80 gallons. The City of Boca Raton Building Department recommends at least a 50 gallon tank heater for a regular size walk-in tub. It says a tank delivers about 70% of its volume as hot water (roughly 35 gallons from 50), and a comfortable bath is about two thirds hot water.
By that rule, the Venzi 30 x 54’s 60 gallon fill needs about 40 gallons of hot water, and the ANZZI 2853’s 70 to 80 gallons needs roughly 47 to 53. Boca Raton adds that BTU or wattage affects only recovery time, that tankless units need high flow and about a 70 degree F rise, and that a mixing valve can stretch an existing tank.
An inline heater will not fix a short supply. The ANZZI sheets and manual say it only maintains temperature and will not heat cold water.
Electrical for air, whirlpool and heater models
Soakers need no power. The ANZZI sheets list 110 volt service with one 15 amp GFCI for an air or whirlpool tub, and one 20 amp GFCI for whirlpool with heater or whirlpool and air. The manual adds a dedicated 15 amp GFCI circuit for the inline heater, 12 gauge three conductor cable, and moisture proof junction boxes 6 inches above the floor at the pump end, out of reach from the tub. It requires a qualified electrician and wiring to the National Electrical Code and local codes. Your electrician and local inspector have the final word.
Leave access to service the pump, as the manual requires.
Wall surround and extension panels
The manual says every tub must have a tile flange, attached with silicone before the tub goes into the alcove. The Venzi 30 x 54 and Artisan list a built in flange, and the ANZZI Coupe Premier air jetted listing says a tile flange is included. The Coupe Premier soaker, Venzi 32 x 38 and wheelchair accessible listings say no tile flange; ask your installer how to add one. Extension panels close the gap to the end wall.
Walk in tub installation order, step by step
- Inspect on delivery; the manual says report damage within 5 business days.
- Water test first: fill above the highest jet, wait 30 minutes, and run jets for 10 minutes while all sides are visible.
- Remove the old tub and confirm drain rough-in and power at the pump location.
- Frame the alcove and attach the tile flange.
- Connect the waste, overflow and door drain.
- Set and level the tub, then make supply and electrical connections.
- Finish the surround and test in place. Per the manual, installation is not complete until then.
Timeline, permits and inspection
The manuals we opened give no install time, so ask your contractor for a schedule. Plumbing, electrical and water heater work often needs a permit. Boca Raton, for example, asks contractors to state the water heater size and filled tub gallons for permit review. Check with your local building department.
What a pro does vs DIY
The manual says a licensed or certified contractor must install the tub, and the warranty in the manual linked from our 53 to 60 x 26 listing is void without a licensed installer. You can measure, clear the path and remove the old tub; leave drains, supply lines and circuits to pros. Still choosing? See our best walk-in tubs for seniors, our comfort height toilet guide, or every ANZZI walk-in tub.
Frequently asked questions
Will a walk-in tub fit my standard bathtub space?
Often. ANZZI’s 53 to 60 inch models include a 7 inch extension kit for a 60 inch retrofit. Compare your alcove to the outer size on the spec sheet.
How big a walk in tub water heater do I need?
Boca Raton’s building department recommends at least a 50 gallon tank for a regular size walk-in tub.
Does a walk-in tub need a dedicated circuit?
Jetted models do. The ANZZI sheets list one 15 or 20 amp GFCI, plus a dedicated 15 amp GFCI for an inline heater per the manual.
Can I install a walk-in tub myself?
The manual requires a licensed or certified installer, so hire pros for plumbing and electrical.
Need help choosing a tub that fits?
Call us at 866-777-2590, Mon-Fri 9AM-6PM PST, with your alcove size and drain side. Orders of $999 or more ship free by freight; below that, shipping is a $200 flat rate. See our return and refund policy before ordering.
