Hot Tub Wiring

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You finally decided to splurge on a backyard hot tub and all that is stopping you from a day of relaxation is its installation. This article will provide you with all the information you need to install your hot tub, including the circuit box and wiring. Let's get started so you can get your hot tub installed and ready for use.

Hot Tub Wiring Requirements

Before beginning to wire a hot tub, it can be helpful to look at the wiring requirements. The type, size, and power of the hot tub you choose will determine what type of electrical requirements you have. You will likely need between a 50 or 60 amp power depending on how many pumps you have and the size of the hot tub's heater.

Previously, we have discussed about do I need a ground wire in metal conduit? Hopefully that clears all of your ambiguities.

In most cases, you will have to hardwire the hot tub with a ground fault circuit interrupter (GFCI). That is unless you go with a plug-in hot tub.

Before beginning, here are a few things to do:

  • Determine your hot tub spa location: This can help you determine how easy or difficult it will be to install. Learn more about other interior design trends here.
  • Check the voltage potential of your home: This is beneficial in choosing the right hot tub. Some hot tubs can be plugged into a nearby wall. Others need to be connected to the circuit breaker.
  • Electrical inspection: Before installing a wired hot tub, it is a good idea to schedule an electrical inspection. This ensures that your home has the power to add an additional electric panel.
  • Local building code: It can also be useful to know what the local codes are for completing any electrical work. For example, most local codes do not allow you to install a hot tub directly under communication or power lines. This includes installation under overhead power lines in the local area.

You want to make sure you have all the tools you need for installation. Other materials like wiring and tape can make the installation easier. Keep a copy of the owner's manual for additional information.

What Parts Do You Need?

It can be beneficial to gather necessary parts ahead of time. The specific parts you need may vary, depending on your type of hot tub and setup.

However, you will usually need a flexible conduit, a rigid metal conduit, and thermoplastic nylon. You may choose to go with a non-metallic conduit, but it is best to avoid aluminum materials.

A liquid-tight flexible metal is useful for installing wiring in six feet or fewer trenches. A few popular brands of liquid-tight flexible metal are liquid-tight flex or SealTite. You will likely use a non-metallic conduit if you are installing the wiring for a longer distance underground. It should be placed at a minimum of six inches when using flexible metal and a minimum of 18 inches for non-metallic.

Ways to Wire a Hot Tub

You will find two main types of hot tubs:

  • Plug and play spa hot tubs: Plug spa hot tubs don't require a wired installation process. Instead, you plug them directly into a 120V power wall outlet.
  • Wired hot tubs: Traditional wired hot tubs require some electrical work. They come in either a 220V, 230V, or 240V and must be connected to the home's GFCI breaker.

The biggest difference between a plug-and-play hot tub and a wired hot tub is the direct connection with a wired tub. With a wired hot tub, you will need a separate circuit breaker that is dedicated to the hot tub.

There are pros and cons to each type. The plug-and-play is easier to install and its location can easily be moved. However, the wired hot tubs usually have access to a greater power supply and heat output.

How to Choose the Right Hot Tub

So, which one is right for you? Plug-and-play hot tubs may be easier to install, but hot tub users usually enjoy wired hot tubs for the following reasons:

  • They provide extra heating power: If you live in an area with changing seasons, a wired hot tub can give you extra heating power.
  • They are better suited for high frequency: If you use your hot tub a lot, you may find that a wired hot tub can be heated faster and does not wear out as easily.

For these reasons, a lot of homeowners choose wired hot tubs. The direct connection to the spa panel provides more power. While the electrical installation may take some work, once the installation is complete, you can enjoy your personal hot spring.

hot tub with wiring
Image Credit: Kitchen Infinity Photo

How to Wire a Hot Tub

In most cases, a wired hot tub requires the services of a licensed electrician. In addition to ensuring you follow code and safety regulations, a licensed electrician can help you decide the best location for your hot tub installation.

If you do decide to complete the hot tub installation yourself, make sure you know what you are doing and ensure you follow National Electrical Code requirements. You may also need to pull permits.

What Is National Electrical Code?

Before beginning the installation of your hot tub, it is important to know what the National Electrical Code is. The National Electrical Code refers to an accepted code that applies to all 50 U.S. states.

It provides a guideline for electric design and installation that ensures safety. Licensed electricians know both the National Electrical Code and local coding laws.

It can also be helpful to keep a few code requirements in mind when it comes to wiring a hot tub.

For one, always turn off the power supply before beginning installation. Then, plan the location of the hot tub panel.

When choosing the location of your hot tub, always consider where you will place the spa panel. The spa panel should be a minimum of five feet and a maximum of 10 feet away from the spa. Within a foot of the hot tub panel, you will need to dig a trench and install the conduit. Local codes prevent you from digging near power or communication lines.

You are also not allowed to install the wiring directly beneath the hot tub itself. You must also avoid placing wiring or the hot tub directly under any power lines.

Going with a full-size hot tub will usually require that you hardwire the spa into the ground fault circuit interrupter.

You should also never use extension cords when installing the wiring for your hot tub.

How to Install a Hot Tub

Follow these steps to complete the hot tub installation process:

Step 1- Set Up Your Circuit Breaker

The first thing you will do during the installation is to set up your circuit breaker. If you opted for a wired hot tub instead of plug-and-play spas, you will need a different breaker on your panel with its own direct wiring and power supply. Make sure you know the power requirements of the wired hot tub so you can match the right service panel and follow all electrical codes.

Be sure to also designate a specific place in the service panel for the installation of your hot tub breaker. Ensuring you have enough power is important for powering your hot tub.

Step 2- Install an Emergency Disconnect

National Electrical Code requires all wired hot tubs to have an emergency disconnect. This is also known as a GFCI emergency disconnect or a ground fault circuit interrupt. The purpose of the GFCI shut-off box is to quickly disconnect the hot tub in an emergency.

In addition to the GFCI shut-off box, you also want a power shut-off as an added layer of protection in case the GFCI breaker box is not working. This added electrical breaker panel should be a maximum of six feet from the hot tub outdoors.


Step 3- Install an Additional Power Outlet

Another National Electrical Code requirement is for all wired hot tubs to have an additional power outlet that is no more than 20 feet from the hot tub. This extra power outlet adds a level of safety.

Step 4- Connect Your Electrical Lines

Now it is time to complete the electrical wiring. Choosing the right wiring type is important when wiring a hot tub. You can sometimes find the wiring dimensions you need in the hot tub owner's manual. You can also check with a local licensed electrician.

Whatever wires you go with, it is best to avoid aluminum wire. Aluminum wire can be dangerous and it also wears out a lot faster as it inherits metal materials.

While your specific wiring needs for your directly wired hot tub will vary, most hot tubs require a 6 AWG copper wire.

A copper wire is one of the generic types often used in the installation process as it usually meets both local and national codes.

When installing your hot tub electrical equipment, you will also have to run your wires through a conduit pipe. Depending on where you live, you may or may not be able to use metal or plastic pipes. You will also need to do a direct burial of the conduit. The direct burial may be as deep as 18 inches, but specific requirements will vary depending on where you live.

Step 5- Wire the GFCI

Before working with wiring, it is important to turn off all power. Then, add in a new service panel for your GFCI. While some people may skip this step, if you draw too much power from the existing main breaker, it could result in false tripping.

False tripping is not uncommon when wiring a GFCI to a two-pole GFCI breaker. The new breaker should be a maximum of five feet from your hot tub. Pull the electrical wire through the conduit and cover the main breaker panel in the trench. Consider what type of material you need for your outdoor conduit.

If you have to run your wiring more than six feet from the main breaker panel, use a waterproof material that is also non-metallic. You can also use thermoplastic nylon with copper wire.

Step 6- Connect Indoor and Outdoor Conduits

Once you have installed your indoor and outdoor conduits, you will need to connect them. Fish tape can help with pulling your wiring into the spa panel. You may need both an indoor and outdoor conduit. An intermediate metal conduit can also be helpful in connecting the indoor to the outdoor conduit and ensuring the circuit breaker is wired and works properly.

It can be helpful to have someone assist you during this step. This can save you time as they can help with pulling the copper wires through the conduit and into the wall outlet.

Step 7- Connect the Wires

Now it is time to connect the wires. Again, if you're not familiar with electrical work, it may be worth it to contact a professional. Otherwise, you can follow these steps:

  1. Connect the red load wire and black load wire to the circuit breaker box.
  2. Connect the green ground wire and white wires to the service panel. The white wire is also the neutral wire.
  3. Take all four wires and connect them to the GFCI breaker box using a conduit.
  4. Connect the black wire to the GFCI line one.
  5. Connect the red wire to the GFCI line two.
  6. Take the white neutral wire and connect it to GFCI neutral bar.
  7. Connect the green ground wire to the bus bar
  8. Find the white pigtail and green ground wire and connect them to the GFCI neutral grounding bus bar.

Keep in mind, the specific installation and wiring process may vary depending on your make and type of hot tub.

It is not uncommon for people installing a wired hot tub to have difficulty with the neutral wire. Make sure you securely connect the neutral wire to the neutral bar.

Make sure your connections are secure as a bad connection can cause the wires to overheat. This can pose a fire risk.


Step 8- Inspect the Electrical Work

Once you have completed the wiring of the circuit breaker and installed the ground fault circuit interrupter, it is time to check your electrical work. Turn on the power supply and check that everything is working properly. Even if you completed the installation yourself, it can provide peace of mind if you schedule an electrical inspection.

In addition to checking that your installation works, you also want to double-check that your wiring meets all code requirements.

This is also a good time to inspect other parts of the hot tub. This includes the motor and water connections.

Commonly Asked Questions About Hot Tub Installation

Here are a few of the most common questions we receive regarding hot tub installation:

What Kind of Wiring Is Needed for a Hot Tub?

Most hot tubs use either a 50 or 60 amp between 220-240 volts. You will have to hardwire it directly into a ground fault circuit.

What Wire Do I Need for a 50 AMP Hot Tub?

Installing either a 50 or 60 amp breaker requires you to integrate the GFCI and controller box. All hot tubs that are 240V require either a 40, 50, or 60 AMP two-pole GFCI breaker.

How Do You Run Electricity to a Hot Tub?

There are two ways to run electricity to a hot tub:

Low 110V Connection

With a low 110V connection, you simply plug the hot tub power into an outlet. This is commonly used with plug-and-play hot tubs.

220V, 230V, or 240V Connection

A 220V, 230V, or 240V connection is used with wired hot tubs. In this case, it directly connects to the central circuit.

When hard wiring the hot tub, you may use existing wiring, which tends to be the cheaper option.

You may also upgrade the wiring, which consists of installing the circuit, wiring, and outlet or subpanel.

What Size breaker Do I Need for a Hot Tub?

You will need between a 50-60 amp breaker and GFCI to install a hot tub. It is also important to note that it should be on a dedicated breaker.

This means that no other power sources use the breaker. This includes things like appliances, lights, or any other power source.

Connecting a few wires and installing a conduit will get your hot tub up and running in no time. If you're not comfortable installing hot tub wiring yourself or are unsure about the logistics, it may be a good idea to contact a licensed electrician. Installing the wiring wrong can be very dangerous. Evaluate your hot tub and its location and determine the best installation.

Dino Paccino

Dino Paccino

Dino is a lifelong writer and home improvement specialist. He enjoys bringing cutting-edge information on home renovation and remodeling to Kitchen Infinity.

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