How to Install a Whirlpool Tub

A whirlpool tub can be an enjoyable addition and add value to a home. When upgrading a bathroom, many people consider replacing an old tub with a whirlpool tub. However, you should be aware that whirlpool tub installation requires electrical work that is not required for a standard tub. This article will show you how to install a whirlpool tub.


  1. 1
    Decide what size whirlpool tub you wish to install. You can buy a whirlpool tub that fits in the same space as a regular tub. Replacing your tub with a larger size adds steps to the process. However, some people enjoy the extra space of a larger tub.
  2. 2
    Contact your local building department to obtain any necessary permits and find out if there are any special rules regarding whirlpool tubs that you must obey. You will probably need an electrical permit. In some areas, a special wall access to the motor and pump is required.
  3. 3
    Turn off the water to your old tub.
  4. 4
    Disconnect the waste, overflow and water pipe to your old tub.
  5. 5
    Check your P trap, which is the P-shaped curve in the drainpipe that prevents gases from you drainage system from escaping up into your house. Reuse your P trap if it is plastic and in good condition. Replace your P trap if it is metal or in bad shape.
  6. 6
    Remove the old tile.
    • Cover the floor with a drop cloth. Use a plumb line and level to mark the area of old tile that needs to be removed. Make sure that the new tile will cover the joint from the drywall you are about to remove.
    • Use a utility knife to cut through the drywall. If you use a saw, you are more likely to hit wiring or plumbing. Use a pry bar to pull out the tile in large sections or piece by piece. If necessary, you can use a hammer to make a hole in the tile to get you started at the top. Wear safety glasses while you are removing the tile.
    • Check the wall insulation. If it is dry and not moldy, you can reuse it. Otherwise it will have to be replaced. Cover moldy areas of the wall with a formula to preserve wood once they are dry before replacing the insulation.
  7. 7
    Remove the old bathtub.
    • Old tub removal can take place in a few ways. You can take it out whole or break it into pieces to remove it. Fiberglass or steel tubs can be broken into pieces with a reciprocating saw. Cast iron tubs can be broken with a sledgehammer. If you decide to break the tub, you should wear safety glasses. You may also want to wear earplugs.
  8. 8
    Rough-in the plumbing for your new whirlpool tub following the dimensions in the manufacturer's instructions.
    • Draw in your center lines. Make sure they are appropriate for the layout you have planned for your tile.
    • Install a 2 by 4 inch (5 by 10 cm) backing for your faucet using the dimensions recommended in the instructions. If necessary, install tub spout and shower head backers.
    • Assemble the copper pipes and solder them together. If you are soldering onto the valve, be certain to take off the cartridge beforehand. Also, you should wait to solder the tub spout until after you have put in the tub.
    • Check to make certain that the P trap will reach the new drain. If it needs to be extended, extend it at this time.
  9. 9
    Have a registered electrician do the necessary wiring.
  10. 10
    Install new bathroom flooring at this time if you plan to replace the flooring.
  11. 11
    Mark the location of your new whirlpool tub and install the edge supports.
    • Different tubs are leveled in different ways, so it is important to follow the directions that came with your new whirlpool tub. In any case, the floor, not the rim of the tub, should support the tub's weight. Check the underlying structure if the floor is more than 1/2 inch (1.25 cm) out of level. Install the edge supports according to the instructions included with your tub.
  12. 12
    Remove your toilet if necessary to make space for putting in your tub.
  13. 13
    Place the tub and set the drain.
    • If your tub does not fit at first, remove more drywall and then replace it.
    • Roll some plumber's putty into a rope with a diameter of about 1/2 inch (1.25 cm.) place the putty on the base of the drain and then insert the drain through the drain hole. Use a tub drain wrench to hold the drain in place and be certain the putty squeezes out on all sides of the edge of the drain. Tighten the waste line until the rubber seal is snug while holding the drain in place.
    • Mortar underneath the tub and seat the tub in the mortar. Do not put any weight on the tub until the mortar has fully hardened, at least overnight.
  14. 14
    Install the overflow, waste and trap. Tighten all nuts by hand and then give them a quarter turn with slip joint pliers.
  15. 15
    Solder an extra-long copper stub and the tub spout cap into place. Cut the spout to the length specified in the faucet instructions.
  16. 16
    Check for leaks.
    • Connect the faucet handles temporarily. Open the water shutoffs and then turn on the faucets.
    • Check all joints and seals for moisture. If there is any moistness, re-tighten the slip nuts and check joints for broken washers.
    • Fill the tub until it reaches the overflow and starts to drain through it and check to make sure that the overflow doesn't leak.
    • Plug in the electricity for tub and start the jets running. With the jets running, check for leaks again.
  17. 17
    Follow the manufacturer's instructions to use water-head screws or roofing nails to secure the tub rim in place.

Things You'll Need

  • Whirlpool tub and associated whirlpool tub plumbing
  • Plumbing and soldering tools
  • Plastic P trap
  • Drop cloth
  • Plumb line
  • Level
  • Utility knife
  • Pry bar
  • Hammer
  • Safety glasses
  • Earplugs
  • Wall insulation, if necessary
  • Reciprocating saw
  • Sledgehammer
  • Plumber's putty
  • Tub drain wrench
  • Slip joint pliers

Article Info

Categories: Plumbing Drains Waste and Vents