Steaming Hot Tub on Wooden Deck

How much power is needed for a hot tub?

Hot tubs and saunas are great additions to back yards, patios and decks.  But they have special power requirements and not every home’s electrical system can support them.  

The purpose of this article is to outline the electrical requirements for most types of hot tubs available on the market today.  It’s not intended to be an installation guide, but instead you may find it helpful when speaking with your electrician about wiring requirements for your new hot tub.

First, let’s explain what exactly a hot tub is.

What is a hot tub?

A hot tub is a hot cauldron of water, big enough for usually 2 or more people.  They usually are installed on a home’s patio, back yard area or sometimes an enclosed room.  Modern hot tubs typically have a large number of water jets that create a massaging effect on the body.

People enjoy relaxing in hot tubs after a long day at work, and sometimes choose to buy extremely fancy hot tubs that feature insane lighting and sound systems. 

Some people refer to the experience of relaxing in their hot tub as a form of “hydrotherapy”, even though hydrotherapy is actually a medical term for the use of water to treat disease.

The maximum temperature of a hot tub is normally set to 104 ℉, according to, although most people prefer a range closer to 100 ℉.  

Hot tubs are sometimes also called whirlpools or spas.  Occasionally people refer to them as Jacuzzi’s, although that word is actually a trademarked name that refers to specific products.  

What electrical components are involved in a spa installation?

*This article is for informational purposes only.  Make sure you have a qualified and licensed electrician do any electrical work on your home!*

Now that we’ve got that disclaimer out of the way, here are the items involved in the electrical hookup for most hot tubs (or spas, whirlpools if you prefer):

  1. The main electrical service for the home
  2. The main electrical panel, or sub-panel depending on the individual home
  3. A breaker in the electrical panel, which powers the hot tub.
  4. The “spa panel”, which is mounted usually on the wall of the home,which should be at least 5 feet away from the hot tub itself.
  5. A GFCI (ground fault circuit interrupter) breaker installed within the spa panel
  6. Wiring and conduit to connect these items all together

What size of electric circuit do hot tubs use?

Most hot tubs require either a dedicated 240 volt, 50 or 60-amp circuit, meaning that your electrician will need to install a 50 or 60 amp breaker.  In houses that have more than one electrical panel, the best location to install the beaker is usually in the panel closest to the hot tub location.

Some hot tubs are known as “plug and play”, and they’re designed to connect directly to a standard wall outlet. 

How large of a main electric service do hot tubs require?

Homes with 150-amp or 200-amp electrical service can almost always support a hot tub.  You’ll also need space for a 240-volt (AKA “2-pole”) breaker in your electrical panel.

If you’ve got 150-amp service, it’s usually best to have a licensed electrician evaluate your service and panel to make sure it’s ready for a hot tub.  (In Alto Home Inspection’s service area, many houses with 150-amp service have unrelated electrical issues that would make me nervous about installing a hot tub before fixing these issues.)

What type of breaker do hot tubs need?

The National Electric Code requires that circuits powering “wet areas” are protected by Ground Fault Circuit Interrupters (GFCI’s).  For hot tubs, the breaker that the hot tub control panel connects to must have this GFCI protection built in.  Without a GFCI breaker, being in or near a hot tub could be deadly. 

What’s a “spa panel”?

A spa panel is an electrical box that’s installed on the side of the house.  It is wired into the control panel of the hot tub, and should be within view of the hot tub users.  However, it should never be closer than 5 feet away from the edge of the hot tub.

Spa panels usually contain the required GFCI breaker, which should quickly and automatically shut off power to the hot tub if a short circuit causes wiring to come into contact with the earth.

What gauge wire should be used to connect the spa panel to the breaker?

For those hot tubs that require a 50 or 60-amp circuit breaker, the wiring between the home’s electrical panel and the spa panel should be 6-gauge wire.  If smaller wire is used, then the chances of the wire overheating increase dramatically.

How should the wire from the spa panel to the hot tub control panel be run?

This wire should be installed in conduit, buried under the ground or run under the patio.  Make sure the conduit is sized properly, and that it’s installed tightly to the spa panel and hot tub control panel.

How much does a hot tub cost to operate?

According to, hot tubs typically cost around $20/month of electricity to operate.  They report that in some cases, bills of $50/month have been reported. 

In addition to electrical charges, don’t forget that you may need chemicals to keep the water clean.  You’ll also want to have an annual inspection of the hot tub performed by a qualified service company.

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