Hydromassage Bathtub Receptacle & GFCI Calculator

What Part VII asks of a hydromassage tub

A hydromassage bathtub is a permanently installed bathtub with a recirculating pump that fills and drains with each use. The NEC treats it under Article 680 Part VII alone, so the pool and spa rules in the rest of Article 680 do not apply to it, and the general bathroom GFCI rule in 210.8(A)(9) still applies to the room. The three Part VII sections that govern the tub itself are the GFCI and receptacle rule (680.71), the accessibility rule (680.73), and the bonding rule (680.74).

The 6 ft receptacle rule, and the edition catch

680.71 pulls a second class of device into GFCI protection: any 125-volt, single-phase receptacle rated 30 amperes or less that sits within 6 ft (1.83 m), measured horizontally, of the inside walls of the tub. That is the measurement a wall receptacle beside the tub has to clear. Receptacles outside that envelope follow the ordinary rules for the room.

This number has moved. Some older editions and at least one local amendment state the distance as 1.5 m or 5 ft, so a secondary source written against an earlier Code can disagree with the 2020 text. This tool uses the 2020 NEC reading of 6 ft. Always verify against the edition your jurisdiction has adopted, which is the point of the one-line disclaimer above.

Worked example: a second-floor whirlpool tub

A hydromassage tub is set in a master bath. The pump and controls run on their own 20 A circuit from a readily accessible GFCI breaker in the panel, so the 680.71 GFCI, readily-accessible, and individual-branch-circuit checks all pass. A duplex receptacle for a hair dryer sits on the wall about 4 ft from the tub rim, which is inside the 6 ft envelope, so it must be GFCI-protected; here it is fed from a GFCI, so that check passes too. The pump is reached through an access panel in the tub skirt, and the installer wired it with a cord and plug, so 680.73 requires the receptacle to be within 12 in of the opening and in direct line of sight. Finally, the copper water lines and the pump frame are tied together with an 8 AWG solid copper bonding jumper per 680.74. Every applicable check passes, and the tool returns Compliant. Change the access panel receptacle to 18 in inside the skirt, out of sight, and the 680.73 check fails and the verdict flips to Not compliant.

Common mistakes

• Burying the GFCI. 680.71 requires the GFCI to be readily accessible, not hidden behind the tub skirt or a finished panel.
• Sharing the circuit. The tub needs an individual branch circuit, not a tap off the general bathroom receptacle circuit.
• Missing a nearby receptacle. A 125-volt receptacle within 6 ft of the inside walls needs GFCI protection even if it is not part of the tub wiring.
• A cord-and-plug receptacle too far inside the access panel. 680.73 holds it to within 12 in of the service opening and in line of sight.
• Skipping the bond. 680.74 requires an 8 AWG solid copper jumper tying the water-system metal and electrical metal together.
• Reading an old distance. Secondary sources that predate the 2020 edition may say 5 ft or 1.5 m; the 2020 figure is 6 ft.

Frequently asked questions

Does a hydromassage tub need a GFCI?

Yes. Under NEC 680.71, a hydromassage bathtub and its associated electrical components must be protected by a ground-fault circuit interrupter, and that GFCI must be readily accessible. The tub is also required to be on an individual branch circuit. This is in addition to the dwelling bathroom GFCI rule in 210.8(A)(9).

How far from a hydromassage tub do receptacles need GFCI protection?

Under the 2020 NEC 680.71, all 125-volt, single-phase receptacles rated 30 amperes or less that are located within 6 ft (1.83 m) measured horizontally of the inside walls of a hydromassage tub must be GFCI-protected. Some older editions and local amendments used a 5 ft or 1.5 m figure; this tool uses the 2020 reading of 6 ft.

Does a whirlpool or hydromassage tub need its own circuit?

Yes. NEC 680.71 requires a hydromassage bathtub and its associated electrical components to be supplied by an individual branch circuit, protected by a readily accessible GFCI. The circuit serves the tub pump and controls, not general bathroom receptacles.

Does a hydromassage tub need to be bonded?

Yes. NEC 680.74 requires the metal piping systems, the metal parts in contact with the circulating water, and the metal parts of the associated electrical equipment to be bonded together with a solid copper jumper not smaller than 8 AWG. The bonding jumper does not have to connect to a remote panelboard, service equipment, or grounding electrode. A double-insulated circulating-pump motor and small conductive surfaces such as water jets are the recognized exceptions.

Is a hydromassage tub the same as a spa or hot tub under the NEC?

No. A hydromassage bathtub is covered by Article 680 Part VII only, and the rest of Article 680 (the pool, spa, and hot tub rules) does not apply to it. A hydromassage tub is a permanently installed bathtub that fills and drains with each use, whereas a spa or hot tub holds its water. Other electrical equipment in the bathroom follows the general requirements of Chapters 1 through 4.

Related calculators

• GFCI Breaker Sizing Calculator: where dwelling and non-dwelling receptacles need ground-fault protection per NEC 210.8, including the bathroom rule in 210.8(A)(9).
• Bathtub & Shower Zone Clearance Calculator: the NEC 406.9(C) and 410.10(D) zone around a tub or shower for receptacles and luminaires.
• Swimming Pool & Spa Equipment Clearance Calculator: the pool and spa receptacle, luminaire, and switch clearances per NEC 680.22 and 680.43.
• Swimming Pool & Spa Equipotential Bonding Calculator: the 680.26 equipotential bonding grid for pools and spas, the counterpart to the 680.74 tub bond.