What Size Wire for a 60 Amp Hot Water Heater?

Continuous or not?

A fixed storage-type water heater with a capacity of 120 gallons or less is treated as a continuous load for branch-circuit sizing under NEC 422.13, even if it does not run for three hours. Apply 125% of the nameplate current and check the applicable edition and manufacturer instructions.

Select a suitable standard breaker for the required load and confirm both conductor protection and the appliance-specific overcurrent limits; the corrected conductor ampacity must cover the actual load and the termination column must cover the required sizing current.

Read the nameplate, not the marketing

Water heaters list a wattage and a voltage; the current is watts divided by volts. A 4,500 W element at 240 V draws about 18.8 A, and a pair of elements can double that depending on how they are controlled.

Use the actual nameplate rating and the manufacturer's installation instructions — many list a required branch-circuit rating directly.

Frequently asked

Is a 60 A breaker the right size for a 60 A circuit?

Not automatically. Size the overcurrent device for the load (including the 125% factor if continuous), then confirm the conductor is protected at that rating. For a 60 A continuous load the minimum standard device is 80 A. See the Quick answer above for the sizes computed under this page's stated conditions. The next-higher exception is not assumed.

Do I need a neutral at a water heater?

Most residential storage water heaters are 240 V line-to-line and do not need a neutral, but some models with electronic controls do. Check the wiring diagram on the unit.

Why does the calculator say my conductor is not adequate?

Usually because the termination temperature limit caps the usable ampacity, or because the ambient temperature correction reduced it. Lower the ambient, reduce conductors in the raceway, or go up a size.

Related calculators

• 60 Amp Wire Size
• Wire Size Calculator
• Breaker Size Calculator
• Quick reference (PDF)