null Your SEO optimized title

Hot Tub Electrical Installation Hookup GFCI

The way to have 230v hot tub electrical installed is to contact your local electrician.
Following is information to understand the process but under no circumstances is intended to be a how-to for non-electricians as working on any electrical appliance including hot tubs can be extremely dangerous if proper procedure and precautions are not taken.

Electrical Hookup Requirements for Hot Tubs

Most spas will operate with either 50 or 60 amp dedicated service at 220-240 volts.

Hooking up a 230 volt hot tub involves an electrician integrating the main house panel with a 50 or 60 amp breaker, the external GFCI/disconnect box and the spa pak/hot tub controller box.  Be sure that the GFCI should corresponds to the house breaker, so for instance a 60A GFCI should be paired with a 60A house breaker.  Whether 50A or 60A is required depends on the number of pumps and size of heater in the spa.

For most exterior spas, the electrician will run a 4-wire number 6 or number 8 wire to the spa location.  The size of the wire to be used is determined by the maximum current draw of the hot tub, the length of the wire run and the NEC or local codes. Use thermoplastic nylon (THHN) insulated copper wire, never aluminum.

We offer a 50 amp load center with GFCI, or a 60 amp load center with GFCI, both by Siemens.

Learn more about hot tub GFCI.

See our current collection of GFCI load centers, GFCI power cords and GFCIs.

gfci hottubs spasGFCI - Ground Fault Circuit Interrupter

Check your local code requirements when installing a GFCI/load center. Typically: Within 10 feet of the spa, but no closer than 5 feet and within line of sight, a GFCI or ground fault circuit interrupter and manual disconnect/shutoff will be installed depending on local code requirements. 

The GFCI installed in this exterior spa panel (load center) that is used for hot tubs is of the 4 wire type.  It contains a ground and a neutral since many spas have 110v components built in to them that require a neutral wire.

Note that the test buttons on the GFCI can also function as a required shutoff.

The GFI will compare the outgoing power against the returning power on the other leg.   4-wire hot tub systems exist because there may be both 120v and 230v components in the spa.  The 4 wires are Line 1, Line 2 (usually black and red), a white neutral wire and a green ground wire. 

So the potential difference between the two power lines is 240 volts to operate the powerful 240 volt heater in the spa, but the Line 1 to neutral difference is just 120 volts to power 120v equipment such as an ozonator or even stereo system.

Siemens GFCI

Not all spas operate on 4-wires, and many older spas only had 3 wire service. Never connect a 4-wire hot tub to 3-wire service.  Other spa brands such as Hot Springs may require 2 independent lines which would then require 2 seperate GFCIs as per their own instructions.

The disconnect junction box with GFCI provides a safety shutoff near the spa.  This shutoff/ spa panel with GFCI is within a line of site of the hot tub, but not closer than 5 feet nor further than 10 feet away usually.  Some are tempted to install the GFCI in the breaker box, but it is best to have the GFCI and shutoff near the spa and per code. In the case of GFCI tripping, it is easier to troubleshoot when installed near the spa as well. 

Note that all 120 volt plug and play spas that operate at 110v-120v have a 15' GFCI cord included with the spa, so an external GFCI is not needed.

The GFCI is a safety device that can disconnect the power completely if a fault is detected. A wiring diagram of the circuit board and connections may be provided on the inside cover of the spa pack or in the hot tub's owners manual.

Get a weatherproof 60 amp GFCI/Disconnect box here:

Hot Tub Wiring and Conduit

Hot Tub WireParts and wiring needed for the electrical installation may include flex conduit, rigid PVC conduit and fittings as well as either #6 or #8 THHN stranded copper wire (never use aluminum) depending on your spa, length of the wire run and local code. Your electrician may also need PVC cement and electrical tape. 

Regarding conduit, for hot tubs, flexible may be used if the run is under 6 feet. The types to use include liquid-tight flexible metal conduit (liquid tite flex or SealTite) or liquid-tight flexible nonmetallic conduit in lengths of no more than 6 feet.

Flex conduit is typically used inside the spa to run the wire from the exterior wall condulet to the spa pack/controller. 

For longer runs underground, install underground wiring in rigid metal conduit,intermediate metal conduit or a nonmetallic system that is listed for direct burial such as 1" rigid Schedule 40 PVC electrical conduit.

This type of conduit needs to be buried at a minimum depth of 6 inches for metal and 18 inches for nonmetallic conduit. The combination of rigid PVC conduit combined with short length of flexible is used as code permits. 

Note that a frost expansion joint (PVC expansion joint) may be required at the point where conduit comes out of the ground and enters a wall or wall mounted panel.

Understanding the Installation Process and Code

The electrician's installation process includes turning off the power at the main breaker and mounting the hot tub panel 5-10 feet away from the spa, within the line of sight.  A conduit trench is dug (being sure to check with local utility company to assure there is no buried cable or pipe there) from the foot of the disconnect box to the spa.  Some spas will allow the interior routing of cable once you get to the spa cabinet.  Note that it is never permitted to run underground wiring underneath a hot tub. 

Another issue is to avoid placing the spa under any overhead power or communication cables as the code does not allow for any overhead electrical/comm. cables within 22 1/2 feet from the top of the water level of the filled spa.

Fish tape is often used to pull the #6 or #8 wire. 

Wiring the GFCI - Electricians take heed and see the diagram above or the diagram in the owners manual regarding proper GFCI wiring for hot tubs.

The tricky part is wiring the 4-wire GFCI correctly used for most hot tubs. The confusion lies in the way the neutral wire is handled in addition to Line 1, Line 2 and ground wires.  See the Hot Tub Outpost video with more tips on wiring up a hot tub GFCI.  The white neutral wire from the back of the GFCI should be connected to the incoming service neutral wire, not the ground bus bar.  The GFCI will not work without this connection of incoming service neutral to back of GFCI.  Load 1 input wire goes to load 1 terminal, load 2 input wire goes to load 2 wire.  For the output section of the GFCI breaker, the load 1 output wire goes to line 1 of the spa and the load 2 output wire goes to line 2 of the spa. The load neutral output provides the 120v difference between the Line wires and is connected to the Neutral White terminal on the circuit board, spa pack as directed by manufacturer instructions. Looking at the bottom of the GFCI, the incoming neutral wire attaches to the white terminal under the black connection so the outgoing neutral wire attaches to the other white terminal under the load out red which runs to the neutral terminal on the circuit board/spa pack. The ground wires need to be properly hooked up to the grounding bus bar.   This information is for licensed electrician reference only. 

Hooking up the wire to the spa involves adding the 2 power wires, neutral and ground wires routed through the 1 3/8" circular hole on the left side of the control box/spa controller (found in many Balboa systems) to the appropriate lugs on the circuit board or routed to the spa pack or controller as per manufacturers instructions. The section(s) of wire that connect the GFCI/disconnect box to the spa must run not only to the hot tub, but to the spa pack located under the cabinet of the spa.  Allow a couple of feet of slack to avoid short or stretched wire.

The 50A or 60A circuit breaker is installed into the main panel (with power off - care is taken since the actual feed wires from the power company are still live even if the panel is off). 

Electrical inspection will assure your spa is safe before using it.

This is another handy diagram for electricians to review before hookup up the 240v GFCI and shutoff.

240v gfci-setup
240v GFCI wiring example

As with any electrical job, it is best to use the services of a licensed electrician to avoid damage to equipment, injury, death.  Many municipalities and cities may require a building permit for installing a hot tub outdoors, so check with your city to see if that is the case or not.

The cost of installing hot tub wiring can vary from region to region and from electrician to electrician, so it is best to get a few estimates.  The wiring can cost several hundred dollars in parts, plus conduit and fittings.  The labor can also run $300-$600 or more.  The GFCI panel is available at the best price from Hot Tub Outpost.

Some reference codes for hot tubs:

Hot Tubs - NEC Electrical Codes excerpts:

680.12 and 680.42 A disconnect must be installed within sight of Hot Tub.

680.42 Outdoor Installations

(A) Flexible Connections Listed packaged spa or hot tub equipment assemblies or self-contained spas or hot tubs utilizing a factory-installed or assembled control panel or panelboard shall be permitted to use flexible connections as covered in 680.42(A)(1) and (A)(2). (1) Flexible Conduit Liquidtight flexible metal conduit or liquidtight flexible nonmetallic conduit shall be permitted in lengths of not more than 1.8 m (6 ft).

680.44 GFCI protection is required for all Hot Tubs and spas.

680.44(A) A Packaged Hot Tub Assembly Unit with a GFCI requires a GFCI Protected Circuit.

There are more codes in article 680 of the National Electrical Code (NEC).

Use of the above content is for information purposes only and releases the author or company employees from any liability.  There is no warranty for the accuracy of this material and it is best to hire a licensed electrician to install the wiring.  Also refer to our terms and conditions regarding technical information provided on this site for information purposes only. Working on any electrical appliance including hot tubs can be very dangerous and should be left to trained service technicians or licensed electricians.

Get a 60A GFCI here.

Contact us at with any questions about the proper installation of your spa.

Horse Sense
Warning: Working on your own appliances, cars, covered wagons and hot tubs as well as anything else electrical or mechanical carries with it severe risk of injury or property damage. These tips and suggested procedures are free and for informational purposes only. Proceed at your own risk. It is best to use the services of an electrician or tech. Hot Tub Outpost is not liable for any damage or injury that may result.

After the Installation

Once your spa is wired up and ready to go, it will need to be filled with water and you will need a spa chemical kit. Choose either bromine or chlorine as your main sanitizer.  See more info on maintaining a hot tub.

Clean Out the Plumbing Lines - Especially Important to use a Biofilm Cleaner like Ahh-Some when buying a used spa or when hooking up either a brand new spa that had test water at the plant run through it, or a spa that has been sitting for awhile.

Getting the spa refilled after fixing the electrical setup? See Ahh-Some as a treatment for getting rid of hidden biofilms and other contaminants in the plumbing lines.  This should be done annually on any brand of spa.  Also use AhhSome on any newly acquired spa or used spa. Even factory new spas benefit from a run-through cleansing with Ahh-Some since factory test water is also not always the cleanest.

Whenever you need any hot tub parts, you will find one of the largest selections of spa parts and accessories in the United States right here at Hot Tub Outpost.