What size wire is needed for electric water heater?

Asked By: Nahara Axnicht | Last Updated: 12th June, 2020
Category: home and garden home appliances
4.3/5 (10,171 Views . 28 Votes)
Common Current and Wire Gauge Sizes
Wire a hot water heater with wire that's sized to accommodate the heater's current requirement. For example, a 20-amp hot water heater needs 12- gauge wire , a 25-amp hot water heater requires 10- gauge wire , and a 30- to 40-amp hot water heater requires 8- gauge wire .

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Likewise, what wire do I use for an electric water heater?

Electric hot water heaters typically require a dedicated 30-amp, 240-volt breaker. The wire supplying power from the breaker panel to your water heater will usually be a 10/2 Romex cable (Blk wire - hot , Marked White wire - hot , Bare copper wire - ground).

Beside above, what size wire do I need for a 4500 watt water heater? A 4500- watt element requires 10/2 wire and a 30 amp (220volt) breaker . The 3800 can be wired with 12/2 wire and a 20 amp breaker .

Consequently, what size wire do I need for a 50 gallon water heater?

The standard for water heater circuits is #10, two conductors with ground (10/2) and a 30 amp circuit breaker for a water heater . If you are running cable anyway, just run #10 and replace the breaker so it's done right, once and for all.

How many amps is a 50 gallon water heater?

Most 50 amp water heater will come with 4500 watt elements. On a 240 volt circuit that is 4500 / 240 = 18.75 amps , so, no, that will not trip a 20 amp breakers, however, it will be operating the breaker nearly 95% of its 20 ampacity rating and most breakers are not rated for that.

39 Related Question Answers Found

What happens if you wire a water heater backwards?

If you reverse the flow from the way the heater is designed, then the cold water comes in at the top and hot water is drawn from the bottom. Since the heating priority is at the top, you don't get as much hot water as you should.

What size breaker do I need for a 40 gallon electric water heater?

It may say on the side of it also. How many watts? Your average residential 30 or 40 gallon water heater is 4500 watts and usually goes on a 30 A breaker .

What size breaker do I need for an electric water heater?

Electric water heaters require a 240-volt dedicated circuit, which serves only the water heater and no other appliances or devices. The circuit wiring typically includes a 30-amp double-pole breaker and 10-2 non-metallic (NM) or MC cable.

What gauge wire do I need for 220 volts?

If you're wiring a 220v, 20-amp outlet to run power tools, you can use the same 12- gauge wire you would use for a 110- volt , 20-amp circuit. Remember that the cable must have an extra hot wire . If the appliance draws 30 amps, you need a different type of receptacle, and the cable needs to be 10- gauge .

How many amps is a 40 gallon electric water heater?


So a 16 amp heater should be wired and protected by a 20amp circuit or a 20 amp breaker should only feed a max of 16 amp load. Bottom line, For a 4500w heater w/240v it will draw 4500/240 or 18.75 amps so #10 wire and either 25 or 30 amp breaker, depending on code.

Can I use 10 3 wire for a hot water heater?

With a 10/3 conductor. But there's no neutral connection on the water heater just a ground. In a cable assembly it is still code compliant to re-identify the white as a hot conductor. In conduit you would need to use the proper colors for the hots.

What size breaker do I need for a 3000 watt water heater?

A 3000 watt 240 volt can be operated on a 14/2 cable, 15 amp double pole breaker .

What size wire do I need for a 5500 watt water heater?

The math shows that 5500 watt water heater is well within the safe maximum for a 30 amp breaker and 10 gauge wire . When heat exceeds circuit breaker rating, then the breaker trips. A 30 amp breaker with 10 gauge wire has 80% safe maximum = 24 amps. 24 amps x 240 volt = safe maximum 5760 watts .

What size breaker do I need for a dual 4500 watt water heater?


4500 watt elements REQUIRE 30 Amp dual pole breaker and 10 Gage wire size .

What size breaker do I need for a 240 volt water heater?

Since this is a purely resistive load 5500 watts at 240 volts is 23 amps, breaker is sized at 30 amps and 10 awg wiring is used. In your case if the elements are strapped for 4500 watts draw is 18.75 amps, permanent draw loads should be sized at 80% of breaker capacity so a 20 amp breaker is limited to 16 amps.

What is the difference between a 4500 watt and 5500 watt water heater?

The higher the BTU input and efficiency, the faster the recovery. Electric water heaters typically have one 5,500- watt or two 4,500- watt elements. Two lower-kilowatt elements will heat much faster than one higher- wattage element.

What size wire do I need for a 40 amp breaker?

“Twelve-gauge wire is good for 20 amps , 10-gauge wire is good for 30 amps , 8-gauge is good for 40 amps , and 6-gauge is good for 55 amps ,” and “The circuit breaker or fuse is always sized to protect the conductor [ wire ].”

What gauge wire should I use for 240 volts?

Use 12- gauge wire for a 20-amp circuit, 10- gauge for 30 amps, 8- gauge for 40 amps, and 6- gauge for 50 amps. Check local codes for requirements.

How many amps does a 110 water heater use?


Unfortunately, the average electric tankless water heater needs at least 120 amps to operate and the average household's total capacity is 200 amps . This means you will have to upgrade your electrical system to accommodate for the larger load demand, which could cost you up to $1,500.

What size wire do I need for a 30 amp breaker?

Any circuit fused for 30 amps must use a minimum of 10 ga copper or 8 ga alu. Longer runs may require an upgrade of wire size . In your case, use at least 10 copper for your welder regardless how far it is from the breaker panel.

What size breaker do I need for a 2000 watt water heater?

The bottom line is, a 2000 watt 120 volt water heater should be on a 30 amp circuit consisting of #10 wire and a 30 amp single pole circuit breaker .
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