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Does a Hot Tub Need a GFCI Breaker?

By: Author Jeff Campbell

Posted on  - Last updated:

Categories Hot Tub Installation

Once you have found the perfect hot tub, it’s time to plan out the installation! You may also be wondering about the electrical wiring of the hot tub. For example, does a hot tub need a GFCI breaker?

All hot tubs require a GFCI breaker. Hard-wired hot tubs will need the GFCI breaker inside a disconnect box located at least 5 feet from the hot tub. Plug-n-play hot tubs will need a GFCI breaker that also has a waterproof covering. 

But there’s a lot more to know than just that. So let’s investigate a little further.

Are there certain laws that pertain to hot tubs? In fact, there is. According to the National Electrical Code, a hot tub is required to be GFCI protected. They also have additional guidelines that depend upon if you are installing indoors or outdoors.

Keep on reading to find out all you need to know about GFCI’s and hot tubs!

What is a GFCI breaker in a hot tub & are they necessary?

A GFCI breaker is also known as a ground-fault circuit interrupter. A GFCI will automatically cut the power if a ground fault occurs. Since hot tubs involve water, the GFCI breaker is critical in preventing electrocution in the event of an electrical issue.

A ground fault happens when an electrical wire carrying electrical current touches a ground wire or other grounded component or part. Also, it can be caused by an overloaded circuit, damaged wiring, or exposure to moisture and dust.

When a GFCI detects a problem with your electrical connection, such as a ground fault or a short circuit, it interrupts the circuit and cuts off all electricity to your spa.

All hot tubs require a GFCI, so yes, they are very necessary. They can help stop accidents and disasters. Always consult an electrician or a professional hot tub installer. Electricity is dangerous to work with, especially near water.

Wondering if you need a stand-alone disconnect box or not?

Luckily, I break that down too in a recent article. I even get into whether or not you need either with an inflatable hot tub or other types of plug-n-play hot tubs.

Just click that link to read it on my site.

Does a plug-in hot tub need a GFCI breaker?

Yes, a plug in-hot tub does need a GFCI breaker. According to the National Electrical Code, any outlet that supplies power to a hot tub is required by law to have a GFCI breaker. This includes plug-in hot tubs too.

Here are the GFCI requirements for an indoor hot tub:

1. Distance

First, there must be at least one convenience receptacle located between 6 to 10 feet from the inside wall of the hot tub.

2. GFCI

Second, the receptacle must be GFCI protected.

Here are the GFCI requirements for an outdoor hot tub:

As with indoor, you must have at a minimum, one convenience receptacle that is located between 6 to 10 feet from the inside wall of the hot tub. Again, this receptacle must be GFCI protected.

1. Waterproof covering

Third, Any outdoor receptacles that are exposed to the elements must have a waterproof covering. This is typically just a plastic shell that is hinged to allow it to open and close but closes automatically.

2. Cord length for plug-in hot tubs

Fourth, an outdoor hot tub can a plug-in type, as long as the receptacle is GFCI protected and the cord does not exceed 15 feet in length.

3. Conduit

For permanently wired hot tubs, liquid-tight flexible metal or nonmetallic conduit is allowed as long as the disconnect box is less than 6 feet away.

When it’s further away, you must use rigid metal conduit.

But again, I am not an electrician, and codes may have different requirements in your area. Always consult with a licensed electrician before doing any electrical work.

What size breaker do I need for a 220v hot tub?

A 220-volt hot tub requires a 50 AMP breaker. This is typically located in a disconnect box located at least 5 feet from the hot tub but within eyesight. The disconnect box is then, in turn, wired to the main breaker panel.

Hot tubs operate on a 220v-240v GFCI protected circuit.

There are exceptions that require as much as 80, 90, or even 100 AMP breaker circuits. This is only if the hot tub has multiple heaters, pumps, controls, etc.

A 50 amp capacity should be sufficient for the majority of hot tubs. However, the higher amperage capacity can be useful to people in colder climates, or those who have large tubs.

Always ensure that you are complying with the National Electric Code, in addition to any local or state electrical codes. Additionally, always consult a licensed electrician, as well as your hot tub manufacturer and owner’s manual.

Believe it or not, but 220v hot tubs use a lot less electricity than 110v.

Want to project how much your electric bill will go up each month adding a hot tub? To see how much electricity a hot tub uses per month, read this recent article.

Just click that link to read it on my site.

How do you hook up a GFCI to a hot tub?

Cut power to the house, mount a disconnect box at least 5 feet from the hot tub, bury flex conduit in the ground from the box to the hot tub. Run conduit from the box to the main breaker panel & pull wires from the hot tub to the disconnect box & from the box to the main breaker panel. Connect wires & restore power.

But that’s just a quick overview, so in a second, we’ll review this step by step.

Like all electrical projects, you are required to follow local codes and consult an electrician before you begin to wire a hot tub disconnect. You must also have the wiring inspected before using the hot tub.

Electricity and water are a dangerous combination, so do not fill the hot tub until it is wired and inspected.

Most electrical codes require hot tubs to be at least 10 feet from overhead power lines. While you can wire your own hot tub, it is strongly recommended that you hire a professional to do it.

However, here are the basic steps involved:

1. Cut the power to the house

To begin with, turn off the power to your home at the breaker box.

2. Mount the hot tub disconnect panel

Next, mount the hot tub disconnect. Follow the instructions that come with your hot tub panel and mount it on the wall of your house. It should be no closer than five feet from the hot tub location but in line of sight of the hot tub.

This distance is required to reduce the chance of someone touching the panel while in the hot tub.

3. Dig a trench for the conduit

Third, you will need to dig the conduit trench, unless the conduit can run under a deck directly to the box.

Ensure you consult your local building code to determine the depth for laying the conduit. Also, contact your local utility companies to make sure you do not cut into a buried utility cable or pipe. Some conduit trenches need to be eighteen inches deep.

Carefully remove the sod and cut it into manageable squares. Set it beside the trench.  Use a shovel and dig the trench for your conduit. Or rent a trencher from Home Depot to make it even easier.

You do not need (in most places) to trench the conduit from the disconnect box to your main breaker panel. You just need to trench the conduit from the hot tub to the disconnect. Do not run a wire or conduit under the hot tub.

4. Run the conduit

The fourth step is to run the conduit.

Use a hole saw to drill a hole through the outside wall near the breaker panel for the conduit to exit the house. If you have a breaker panel outside your home, this is not necessary.

Measure, cut, and cement the necessary conduit and fittings to run from the breaker panel down the wall to the disconnect box.

Then run conduit in the trench between the disconnect and the hot tub.

If either conduit runs under 6 feet, use liquid-tight flexible metal or non-metallic conduit. Do not use lengths more than six feet. For longer runs underground, use rigid metal conduit, or intermediate metal conduit. PVC is also a popular conduit material that you can use if allowed by your local codes.

Insert an LB fitting in the hole in the wall to connect the indoor and outdoor conduit. Make sure you have the wiring inspected by a professional before burying.

5. Pull the wires

For step five, you will pull the wires.  Copper wire with THHN (thermoplastic nylon) insulation is recommended. Ensure you avoid aluminum wire. The recommended hot tub wire size is six AWG copper.

Make sure you use fish tape to pull the wires from the fitting to the hot tub panel. Leave at least six inches of extra wire hanging from the hot tub panel.

Push the wires through the LB fitting into the house and to the breaker panel.

Then use fish tape to pull the wire through the conduit from the spa panel to the control panel on the spa. Leave at least six inches of extra wiring on either end.

6. Wire the disconnect to the main panel

The sixth step is to wire the disconnect box to your main breaker box. Attach the wires that lead to the disconnect. Attach the red, white, and black wires to the bottom of the GFCI breaker. Then attach the green grounding wire to the ground bar.

Attach the wires from the breaker panel. Then attach the black and red wires to the breaker feed lugs on top of the breaker. Ensure you attach the white wire to the line neutral bar. Then attach the green grounding wire to the ground bar.

Be sure to follow your spa panel and spa instructions when wiring the panel.

7. Wire the hot tub 

The seventh step is to wire the hot tub control box located under the hot tub. Simply follow instructions given to you by the manufacturer.

Typically, the flexible conduit would feed up through the bottom of your hot tub to your control box, usually located in the middle behind one of the panels. There should be a knock-out hole for the conduit to feed through. The wires would then get connected according to your manual and manufacturer.

The second to last step is to wire the hot tub panel to the breaker panel. Make sure the main breaker is off and that there is no power present. The wires coming from the power company are still energized, even with the breaker off.  Always be careful when working in the breaker box. Attach the red and black wires to a dedicated double-pole 240V GFCI circuit breaker. Label the new hot tub circuit breaker.

The final step is to have the hot tub inspected by a professional before filling it with water and using it.

How far away does a GFCI have to be from a hot tub?

A ground-fault circuit interrupter must be at least 5 feet away from the hot tub, as required by the national electrical code. Typically any electrical cords would be buried in the ground, but for any above ground, they must not pass over the hot tub.

But again, the requirements are different for plug-n-play hot tubs such as inflatable hot tubs and other kinds of plug-in hot tubs.

Hard-wired hot tubs will need a disconnect breaker box, which will contain a GFCI breaker inside of it.

And the requirements are also different if you are placing yours indoors. If your hot tub is indoors, the distance requirement is 6-10 feet.

If you are considering an inflatable hot tub, it’s not uncommon to wonder if they are worth it?

Luckily, I break down all the pros and cons for you in this recent article. They can be very inexpensive, and a great way to start hot-tubbing when your budget is low.

But there are still a lot of potential issues you’ll want to steer clear of. Just click that link to read it on my site.

Final Thoughts

A GFCI is also known as a ground-fault circuit interrupter. A GFCI will automatically cut the power if a ground fault occurs. GFCIs are required for all hot tubs.

According to the National Electric Code, any outlet that supplies power to a hot tub is required by law to have a GFCI breaker. This includes plug-in hot tubs too.

A 220-volt hot tub usually requires a 50-amp breaker. Always consult professional electricians both before and after wiring your hot tub.

Photos which require attribution:

Ground Fault Circuit Interrupter (GFCI) Electrical Outlet by Tony Webster and Outside Breaker & GFCI for Pier by bobcapra are licensed under CC2.0

Jeff Campbell
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