How to Wire a Hot Tub

How to wire a hot tube
How To Wire A Hot Tub

Warning: Wiring a hot tub is an advanced job. Most electricians that attempt to wire a hot tub will get it wrong.

Make sure you hire a certified local hot tub electrician that is familiar with the building codes and experienced in wiring spa tubs to guarantee your safety.

It is also important to note that this is typically a two-man job. A professional crew should be able to complete this project in 4-8 hours. To speed the process a third person is recommended.

Tools And Materials You Will Need To Install Hot Tub Wiring:


  • Marker
  • Knife
  • Wire Strippers
  • Screwdrivers
  • Hole Saws
  • Power Drill
  • Impact Drill
  • Wood Drill Bits
  • Masonry Drill Bits
  • Saws All
  • Shovels
  • Gloves
  • Tape Measure
  • Fish Tape
  • Flash Light
  • Conduit Heater
  • Level


  • Electrical Tape
  • Conduit
  • PVC Glue
  • Breakers
  • Wire
  • Manual Disconnect Box
  • Seal Tite Conduit
  • Pipe Fittings
  • Pipe Straps
  • Masonry Screws
  • Drywall Screws
  • LB Conduit Body
  • Wire Nuts

What Does The National Electrical Code Say About Hot Tub Wiring

The National Electrical Code or NEC requires that hot tub installations meet their regulatory safety standards. It is important to follow these codes and your local codes very closely.


  • Any outlet supplying power to the tub must be GFCI protected
  • Installation of an approved manual disconnect device must be within line of sight of the spa.
  • The disconnect must be adjacent to the tub and no closer than 5 feet away.
  • Buried wires must be at least 18 inches deep.
  • Bonding: the neutral and ground are bonded only in the main breaker panel at the designated bonding point

Step One: Plan The Installation

Planning the installation is simple but important. Your electricians are going to need to determine where to place the disconnect and how to run the wires from the panel, through the disconnect, and into the hot tub.

Does The Wire Go Inside Or Outside?

An experienced hot tub electrician will determine the shortest distance from the panel to the disconnect. The wire can be run through the inside of the home either in the attic, through a crawlspace or in the basement. If the wiring is run through a basement or crawlspace a hole will need to be drilled through the foundation. This is going to require a large impact drill with a masonry drill bit that is large enough to allow the conduit to pass through.

Where Does The Disconnect Go?

According to the national electrical code, the disconnect must be adjacent to the hot tub, in the line of sight of the hot tub and no closer than 5 feet away. Our electricians will typically place the disconnect on a nearby wall and try to make it where it is somewhat out of the way but still in a safe location.

Where Does The Conduit And Wire Go?

We usually try to hide or bury the conduit coming from the panel to the disconnect as well as to the hot tub. We do this either by trenching 18 inches down and running any conduit that we can inside the house’s crawlspace or basement.

The conduit coming from the panel may be visible, depending on the installation path.

The hot tub tail will be visible as it goes into the hot tub unless the tub and installation allow a bottom entry point.

Not All Hot Tubs Have Bottom Entry

It’s important to check with the manufacturer to make sure that you can drill a hole into the bottom of the tub. Certain manufacturers place components all across the bottom that will break if a hole is drilled into the bottom of the spa.

Step Two: Install The Disconnect

Mounting The Hot Tub Disconnect

The disconnect can be mounted to a nearby wall or post. Again, the disconnect must be at least five feet away, adjacent to the tub, and within eyesight of the spa.

The disconnect must be level and high enough off the ground to enable the conduit and wires to enter and exit without interference. Open the disconnect, find the holes on the backside for attaching the disconnect to the mounting surface, mark the holes and screw the box in place.

Step Three: Install The Wiring And Conduit

Where Does The Conduit Go?

The conduit is used for any wiring that runs outside of the house. Typically an outdoor run will come from the backside of the main electrical panel, through the siding of the home and into an LB conduit body. The rest will then be trenched to the disconnect. Additionally, another run from the disconnect to the spa is also trenched or run underneath a deck if possible.

In the case of an indoor wire run, the conduit will start as soon as the wire exits the home. A hole is usually drilled through the foundation and then an LB conduit body is used as an attachment point for the conduit. From the LB the rest of the conduit is trenched to the disconnect or strapped along the bottom side of the home if trenching is not an option.

Trenching: How Deep Does The Conduit Have To Be?

The conduit must be buried 18 inches below surface level. This is to protect the wires and anyone who might be digging in the area.

Strapping: How Often Should The Conduit Be Strapped?

Our team of electricians is trained to place a strap every 3 feet of conduit. This will keep the conduit from sagging and prevent any single ten-foot section from coming loose should one strap fail.

Installing The Wire: How Is It Done?

Running Wire From The Panel To The Disconnect

The wire is run from the panel to the disconnect. The wire can be run below the house, above the house, or around the outside of the house. Any wiring inside of the house will not need to be run in conduit. Any wire outside of the house will need to be run in conduit.

The use of a fish tape is absolutely necessary when pulling wire through a conduit. This is also where it helps to have two people. One electrician will be feeding the wire into the pipe while the other is pulling the fish tape.

Once the wire is inside of the disconnect it can be terminated to the appropriate connections inside of the box.

Running Wire From The Disconnect To The Hot Tub

Once the disconnect is terminated the wire will be made into a tail and installed from the disconnect to the hot tub. This section often involves a piece of seal tight conduit aka waterproof conduit that connects directly to the panel inside of the tub.

The wires going into the tub are then terminated at the appropriate connections according to the hot tub’s wiring diagram.

Terminating The Main Electrical Panel Connections

The last step to installing the wiring is to terminate the connections inside the panel. It is important to do this last. If the wires are not connected to the panel during install you reduce the risk of electrocution. Remember Safety first.

Assuming that the electrical panel can handle a new hot tub installation the appropriate breakers are in place, and the correct wires have been used and terminated everywhere else, its time to turn on the power.

Once the power is on it is time to test everything to make sure that the tub is ready to be powered on.

Step Four: Test The Hot Tub Wiring Installation

How Is The Wiring Tested?

The wiring can be tested in a few ways. Using a set of electrical testers an electrician can make sure the wires have no ground faults and proper continuity. Additionally, testing each of the GFCI components is part of the process. Last but not least, after the tub is filled with water, turn on the spa’s controls and activate the jets.

Step Five: Clean Up

Our electricians are trained to never leave a mess. Always try to make the job site look better than when you arrived.

The first step to cleaning up is picking up all the spare parts and any trash that might have been created.

Then the trench can be backfilled and the sod is placed as neatly as possible over the trench.

The final step is to broom the work areas and run a vacuum if needed to collect any dust and debris.

Hiring a Hot Tub Electrician

If you’re in the market for a hot tub or you have already purchased one we would be glad to help you with your spa’s electrical installation.

Our electricians are trained and experienced hot tub electrician’s and they will make sure your hot tub installation goes smoothly and safely.

Contact RU Electrical Service

For any questions you have or if you would like us to quote your install you can reach us by phone, text, or email.