What is a Hot Tub Disconnect and Do I Need One?

When you begin your search for the perfect hot tub, you will come across models that connect to your home’s electricity in different ways. For those that operate on 220 volts, you’ll no doubt end up asking what is a hot tub disconnect and do you need one?

Here’s what I know having owned 4 hot tubs:

A hot tub disconnect is a small breaker box usually located within 5′ of the hot tub. It contains a breaker that allows you to quickly cut power to the hot tub & also provides the extra security of being a GFCI breaker that cuts power in the event of any error or danger. They are needed for all 220-volt hot tubs.

Hot tub models either have a 110-volt plug or a 220-volt model. 110-volt hot tubs just plug into a standard outlet the way any appliance or a small piece of equipment plugs in.

These are often called plug-and-play models.

The 220-volt models, however, which are more common, require some electrical work to be done. For these, the hot tub’s power line won’t run directly to your main breaker panel. Instead, there will be a small breaker panel just for the hot tub.

This small panel, also known as a hot tub disconnect, is usually located close to the hot tub (but not close enough to get splashed). Then that panel gets connected to your main outdoor breaker panel.

Keep on reading to find out more about what a hot tub disconnect is, and if you need one.

What is a hot tub disconnect?

As I said above, a hot tub disconnect is a small electrical box located near (but not too near) the hot tub.

It is the go-between between the hot tub’s electrical system and your home’s main outdoor breaker panel. This small box has a line that runs from the hot tub, and then another line that runs to the main breaker panel.

Inside are the breakers specifically for your hot tub.

It allows you to cut power to the hot tub quickly if you need to. But the breaker inside the panel will also have a ground fault circuit interrupter (GFCI).

This is just a bigger version of the outlets that are likely near your kitchen and bathroom sinks. They have a small reset button and built-in breaker that trips if water comes in contact with it.

GFCI breakers automatically cut power if a ground fault occurs.

For hot tubs, this could be water splashing on the panel. But it also could be from a leak underneath that is causing water to get in the electrical control box.

Other things that could cause this include:

  • A wire carrying electrical current touches a ground wire or anything else that is grounded
  • An overloaded electrical circuit
  • A broken wire

A 220-volt hot tub allows the hot tub to draw more power. In turn, this allows the water to heat faster and more efficiently. Ironically, despite using more power, a 220-volt hot tub will cost less on your electric bill.

This extra power also allows users to run the hot tub jets on high while heating the water. This is a feature that is not possible on the 110-volt plug models.

A hot tub disconnect also allows the hot tub to be easily disconnected from the main power supply.

Do you need a disconnect for a hot tub?

You don’t necessarily need a disconnect for a hot tub.

As previously stated, if you have a 110-volt model hot tub, then you won’t need a disconnect for your spa. But if you have the 220-volt model, then you will need one.

The most common hot tub disconnects are available in a 50 or 60 amp capacity. 

For larger capacity hot tubs (7+ people) with multiple heaters, higher amperage models also exist. However, these are not as common.

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. Make sure you read your owner’s manual to find out what is recommended for your particular model of hot tub.

How far does a hot tub have to be from a breaker?

While a hot tub is a great way to relax and have fun, the installation involves conforming to specific electrical requirements.

The National Electrical Code (NEC) states that a disconnect meant for the purpose of maintenance should be provided within five feet horizontally from any hot tub or spa.

However, the disconnect does not necessarily have to be a circuit breaker, although it absolutely can be.

It can also be a switch. In most installations, a circuit breaker is used for the disconnect, and it would fulfill the NEC requirement if it is located within five feet of the hot tub.

There is no regulation regarding the placement of the breaker if it is within five feet of the hot tub.

All of that being said, different states, cities, and counties sometimes have different codes and building requirements. Your local licensed electrician should know all the local requirements in your area.

Do I need a permit to install a 240v outlet?

The consensus is that yes, you do need a permit.

However, it is important to note as I said above, that each state, and specifically every city, could have different laws and requirements.

That being said, while I would never tell you to do anything unsafe or recommend breaking the law, I can tell you that when I have had hot tubs installed, the electricians involved did not get permits as far as I know.

But it’s always worth checking with whoever is installing your hot tub. You can also do some research online and determine if the area you live in requires you to have a permit.

Different cities and municipalities will require different permitting, so always check before doing any installation. If a licensed electrician tells you to skip a permit, double-check on your own and make sure. They may not actually be licensed.

It is always good to take precautionary measures. Always do your research before any installation.

How do you wire a hot tub disconnect?

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.

Let me reiterate. While I am laying out the steps to follow, this in no way should be interpreted as my advising anyone to NOT hire a licensed electrician or to attempt to do some somewhat serious electrical work themselves.

Always get a licensed electrician to do electrical work and not doing that is doing so at your own risk.

STEP 1

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

STEP 2

Next, mount the hot tub panel.

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.

STEP 3

Third, you will need to dig the conduit trench.

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. When I did this at my last house, I rented a trencher from Home Depot which made this a whole lot easier! Just click that link to reserve one now on the Home Depot website.

STEP 4

The fourth step is to run the conduit.

Lay your heavy-duty rubberized wire in the trench from the panel to the hot tub. Allow enough slack so it is not pulled too tight.

Do not run a wire or conduit under the hot tub.

Assuming your nearest breaker panel is outside AND has an available slot, you’ll also run conduit down the side of your house from the hot tub disconnect to the main breaker panel.

If your conduit runs under 6 feet from disconnect to panel, 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 a popular conduit material that you can use.

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.

STEP 5

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.

Ensure you are leaving at least six inches of extra wire hanging.

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.

STEP 6

The sixth step is to wire the hot tub disconnect.

Attach the wires that lead to the spa. 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.

STEP 7

The seventh step is to wire the hot tub control panel with the wires coming from the hot tub disconnect. Simply follow instructions given to you by the manufacturer.

STEP 8

The second to last step is to wire the hot tub disconnect to the main 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.

FINAL STEP

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

Did I cover all you wanted to know about hot tub disconnects?

A hot tub disconnect is a special outlet required for 220-volt models.

It allows the hot tub to be easily disconnected from the power supply. It also provides safety from electrical shock when in or around the spa.

You don’t necessarily need a disconnect for a hot tub. As previously stated, if you have a 110-volt model hot tub, then you won’t need a disconnect for your spa. Those are sometimes called plug-and-play-models.

But if you have the 220-volt model hot tub, which is the most common, then you will need one.

The National Electrical Code (NEC) states that a disconnect meant for the purpose of maintenance should be provided within five feet horizontally from any hot tub or spa. Different cities and municipalities will require different permitting, so always check before doing any installation.

Water and electricity don’t mix. That being said, you might be surprised to hear it’s sometimes OK to use a hot tub in the rain.

If you’re curious about how rain affects a hot tub and when it’s OK to use one in the rain, check out this recent article. Just click that link to read it on my site.


Photos which require attribution:

Tub23 by Dave Stone is licensed under CC2.0

Jeff Campbell

Jeff Campbell is a husband, father, martial artist, budget-master, Disney-addict, musician, hot tub lover, and recovering foodie having spent over 2 decades as a leader for Whole Foods Market.

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