How Many Amps Does an Electric Water Heater Use?

Electric Water Heater amperage at 120 V and 240 V

Same 4,000 W load: the current halves when the voltage doubles. Electric Water Heater is typically a 240 V appliance in US homes.

Breaker and circuit for an electric water heater

Electric Water Heater runs on its own dedicated 240 V circuit: plan on a 30 A double-pole breaker with 10 AWG copper. Storage water heaters are continuous duty (NEC 422.13, sized at 125%): a typical 4,500 W element needs 23+ A of capacity, and 30 A / 10 AWG is the standard circuit.

Guidance only: actual circuit sizing depends on your unit's nameplate, wire run length, and local code. Confirm with a licensed electrician. See the wire & breaker size chart for the full NEC ampacity table.

Measure what an electric water heater actually draws

The figures above are typical ratings, and this load is usually hardwired or on a 240 V circuit, so a plug-in meter can't reach it. A clamp meter reads the current on one conductor at the disconnect or panel without breaking the circuit; opening a panel is work for someone qualified, and the voltage pen confirms a circuit is dead first.

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Clamp meter

Fluke 323

Best for: Measuring what a hardwired circuit actually draws, even in a crowded panel

Check price on Amazon: Fluke 323 (opens in a new tab)(paid link)

Non-contact voltage tester

Klein Tools NCVT-3P

Best for: Confirming a circuit is dead before you open a device or box

Check price on Amazon: Klein Tools NCVT-3P (opens in a new tab)(paid link)

Frequently asked questions

Amp draw of other appliances

• Well Pump8.3 A
• Sump Pump6.7 A
• Heat-Pump Water Heater2.3 A
• Tankless Electric Water Heater75 A