Home > Library > What to Know Before Wiring a Hot Tub Electricity and water can be a dangerous combination. Electricians and contractors need proper training, familiarity with code and an understanding of the basics such as motors, GFCI and wiring before installing hot tubs. Water and electricity don’t mix — unless you’re dealing with something like a hot tub. And because the potential dangers involved with wiring a hot tub may make most homeowners give pause, there is quite a market for qualified contractors. “When it comes to wiring electricity around water, that’s a big problem,” says Mike Holt, an author and electric code expert. Know the NEC Hot Tub Electrical Code Electricians and contractors need to read and understand the National Electric Code (NEC), especially the sections pertaining to hot tubs. Holt, who receives telephone calls from puzzled electricians on a regular basis, knows firsthand that many haven’t mastered the code as it relates to swimming pools, spas and hot tubs.
In response, Holt created a document that distills the complex language of the NEC for swimming pools, spas, hot tubs, fountains and similar installations and offers it free of charge through his Web site. Scott Hartke, who co-owns Alliance Electrical, based in Wichita, Kan., installs hot tubs frequently. “Once you get the basics down, it’s not hard at all,” he says. There are specific technical requirements to ensure hot tub installers and occupants remain safe. Although electricians should consult the NEC for complete code requirements, there is code that pertains specifically to hot tubs, according to Holt’s document: Emergency shut off: A clearly labeled emergency spa or hot tub water recirculation and jet system shutoff must be accessible to users and located not less than 5 feet away, but adjacent to and within sight of the hot tub. The maintenance disconnecting means or a pushbutton that controls a relay can be used to meet this requirement. Flexible connections: Listed packaged spa or hot tub equipment assemblies or self-contained spas or hot tubs are permitted to use flexible connections as follows: flexible conduit;
liquid-tight flexible metal conduit or liquid-tight flexible nonmetallic conduit in lengths of no more than 6 feet; and cord-and-plug connections with a GFCI-protected cord that is not longer than 15 feet. Bonding: Bonding is permitted by mounting equipment to a metal frame or base. Metal bands that secure wooden staves aren’t required to be bonded. Interior wiring for outdoor spas or hot tubs: Any wiring method, which is outlined in a previous chapter of the NEC, containing a copper equipment grounding (bonding) conductor that is insulated or enclosed within the outer sheath of the wiring method and not smaller than 12 AWG is permitted for the connection to motor, heating and control loads that are part of a self-contained spa or hot tub, or a packaged spa or hot tub equipment assembly. Hot Tub Installation Don’ts Don’t install a hot tub under any power lines. “A lot of people don’t think about that,” Hartke says. “I know when they buy their tub, it’ll say that on their brochures, but I still see people all the time sticking them under power lines.”
Not only is it unsafe, but the practice also violates the NEC. Don’t use underground wiring under outdoor hot tubs. If space constraints prevent wiring from being at least 5 feet away, underground wiring should be installed in rigid metal conduit, intermediate metal conduit or a nonmetallic raceway system that is listed for direct burial. Then it must be buried. The minimum depth is 6 inches for metal raceways and 18 inches for nonmetallic raceways. Don’t install low-voltage lighting within 10 feet of the hot tub, even if it is GFCI protected, which is required by code. Don’t forget to consult state and local codes in addition to the NEC. Be sure to join the Lowe’s ProServices LinkedIn Group to read additional content and interact with other Construction/Trade and MRO professionals. NEXT ARTICLE5 Strategies to Improve Safety in Your SPREVIOUS ARTICLEConverting Residential Homes into CommerHot tubs and spas come in an array of shapes and sizes, and can be equipped with scores of accessories.
Accordingly, they have a wide range of prices. Choosing the right spa depends on its intended use, how big your deck is, and what structural alterations will be required for your deck. In addition, you’ll need to know the cost of installation, day-to-day expenses, and how much you can expect to recoup on your investment should you sell your home.It started with that icon of laid-back living, the redwood hot tub. Before long, fiberglass versions with circulating jets appeared called “spas.” Today the terms “hot tub” and “spa” are used interchangeably, but because most units are jetted, spa is the term more commonly used. Spas range in size from two-person models costing about $2,000, to 20-foot-long swim spas costing $18,000 or more. In between are those most popular for decks: 4- to 8-person models costing from $2,500 to $10,000.Choosing a spa can be challenging. You’ll need to select from a dazzling number of accessories, including cup holders, colored LED lights, iPod docks, stereo systems, pop-up TV screens, and even waterproof keyboards.
“The gadgetry is there to catch your eye while shopping,” cautions Erich Johanson, an experienced spa installer in Olympia, Wash. He recommends choosing established manufacturers and narrowing your choice from there. “Look at the national brands and find one you like,” he says. “Then chose a model that has the features you want.”His top recommendation is for “full-foam” insulation—a high-density, closed-cell polyurethane foam that fills the cavity between the fiberglass tub shell and the outer cabinet and helps reduce heat loss. In addition, full-foam insulation helps reduce noise and adds stability to the entire unit.Check installation costs as well. They’ll be dependent on the size of the spa and the ease of getting it where it needs to be. In some cases, limited access may require the use of a crane to lower the spa into place. For an 8-person spa, expect about $300 for delivery and setup.The safest—and most cost-effective—location for a spa is the lower level of a deck.
A deck only a few steps above ground, if built to code, should be able to support 100 lbs per sq. ft.—a filled 8 x 8 spa at 6,000 lbs. works out to about 94 lbs per sq. ft., just within limits. Check your local codes for any restrictions governing the installation of a spa on a deck.Even better is a reinforced concrete pad, a great option if you’re planning a new deck or intend to add on to an existing deck. A 4-inch slab will safely bear 115 lbs per sq. ft.If you want the tub on a deck more than a couple of feet above ground or on an upper level of a deck, things get more complicated. You’ll need to hire a structural engineer to provide specs for a site-specific framing structure to support the weight. Expect to pay an engineer $300 to $500 for these services. The necessary framing for a typical backyard deck may cost only a few hundred dollars, but expect to pay much more if your deck is a high-flying structure perched on a slope.Spas require a nearby source of electricity. Because water is involved, any electrical hookup for a spa must include ground-fault circuit interrupter (GFCI) protection.
This nifty device shuts down the system within milliseconds if it detects the tiniest change in current flow caused by a short circuit. Some spas come with an extension cord with a GFCI built in that can be plugged into a 110-volt, 20-amp circuit.Larger units require at least one dedicated 220-volt, 50-amp circuit. In addition, there must be an emergency shutoff within sight of the spa, but not closer than 5 feet or farther than 50 feet. A new circuit and shutoff will cost about $800.Water access is simple; spas fill with an outdoor hose. The spa then heats and circulates the water. Insulated tub covers limit evaporation, but the tub will need occasional topping off. When it’s time to empty the unit, all spas have built-in hose bibs so you can drain the water.Getting in and out of a spa provides opportunities for mishaps. A handrail is a good idea for older—and younger—users. A cover with a lock is must if you have children.If you plan to build your spa into the deck, it may seem best to drop it into the deck so that the rim of the tub sits on the decking.
Unfortunately, this makes it easy for people to fall in or step on the cover, and also complicates getting into the tub. The ideal arrangement is to set the spa partially into the deck so the rim is 17 to 24 inches above the decking. That way, bathers can sit on the rim, swing their feet over, and enter the water.Hot water feels great, but needs to be indulged with caution. The Association of Pool & Spa Professionals recommends keeping the water temperature between 100°F and 102°F, with 104°F as a maximum. A safe soaking duration is 15 minutes. To keep the spa free of bacteria, you must be clean it regularly and add sanitizing chemicals.It costs as little 50¢ a day to run a spa. That amount can vary according to the amount of use, your local energy costs, the quality of insulation in your spa, and the quality of the cover. Covers typically come with spas, but consider upgrading to a higher efficiency type. The additional cost is modest and the better-insulated covers are often lighter, making them easier to remove.