14.5 Appliances, Fixed Electric Space Heating & Deicing Equipment (Articles 422, 424 & 426)

Appliances (Article 422)

Branch circuits and overcurrent protection

Example: a 4,500 W, 240 V storage water heater draws $4500 \div 240 = 18.75$ A. Its branch circuit must be rated at least $18.75 \times 1.25 = 23.4$ A, so use a 25 A circuit with 10 AWG copper.

Central heating equipment (422.12)

Central heating equipment other than fixed electric space-heating equipment, such as a gas furnace, must be supplied by an individual branch circuit. Exceptions:

• auxiliary equipment directly associated with the heating equipment, such as a pump, valve, humidifier, or electrostatic air cleaner, may be on the same circuit; and
• new in the 2026 NEC: the circuit may also supply the HVAC service receptacle required by 210.63(A) and the lighting outlet for the service area required by 210.70(C).

DLI's 2026 review also describes the exception as broadened to cover similar associated equipment on the dedicated furnace circuit.

Cord-and-plug connection (422.16(B))

Disconnecting means (422.31 to 422.34)

Fixed electric space heating (Article 424)

Example: two 2,000 W, 240 V baseboard heaters on one circuit: $4000 \div 240 = 16.7$ A; $16.7 \times 1.25 = 20.8$ A. A 20 A circuit is too small, so use a 25 A or 30 A circuit with conductors sized to match.

Heating cables in ceilings, floors, and walls (Article 424, Part V)

Deicing, snow-melting, and pipeline heating (Articles 426 and 427)

Minnesota winters make heated sidewalks, ramps, roof and gutter deicing cable, and heat-traced pipes common:

• GFPE (426.28): ground-fault protection of equipment is required for fixed outdoor electric deicing and snow-melting equipment, except equipment using mineral-insulated, metal-sheathed cable embedded in a noncombustible medium. A 30 mA equipment protective device is typical.
• Pipeline and vessel heating (427.22): GFPE is required for electric heat tracing, with limited exceptions for industrial establishments with qualified maintenance.
• Branch circuits: deicing and snow-melting equipment is a continuous load, sized at 125%.
• Expansion and contraction (Article 426): embedded heating cables and their leads must be protected where they pass through expansion joints and where they leave the embedding material, so movement of the slab does not damage them.
• Disconnecting means (426.50): a means to disconnect all ungrounded conductors simultaneously; it must be of the indicating type and lockable in the open position, and the branch-circuit switch or breaker may serve where readily accessible to the user.
• Conductive pavement heating (new Part VI of Article 426, 2026): systems operating at not more than 30 V RMS or 60 V DC, used for snow and ice melting.
• Outdoor receptacles: a receptacle that is not readily accessible and supplies only a dedicated snow-melting, deicing, or pipeline heating circuit is exempt from the dwelling GFCI requirement for outdoor receptacles, because the equipment already has GFPE.

Worked example: a garage with a heated driveway

A new home has a 4,500 W water heater, a gas furnace, and a 9,600 W heated driveway at 240 V.

1. Water heater: 25 A circuit as calculated above.
2. Furnace: individual branch circuit, which may also feed the required service receptacle and the equipment-area light under the 2026 exception.
3. Driveway: $9600 \div 240 = 40$ A; continuous load, so $40 \times 1.25 = 50$ A. Provide a 50 A circuit with GFPE, unless it uses MI cable embedded in concrete, and a lockable disconnecting means.