How Many Amps Does A Water Heater Use

what size breaker for a hot water heater

Does your electrical h2o heater go on tripping the breaker? Did your heater overload without notice? With just these few questions, it is articulate that you lot're having a problem matching your apparatus with its rubber device.

What size billow for a hot water heater, y'all say? The standard size for most heaters is 30-amps. However, this billow ampacity doesn't necessarily work for every water heater at that place is.

There is a formula for finding the correct breaker size, but at that place are other essential factors to talk about later in this article.

Understanding Your Water Heater

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Upon purchasing an electric water heater, 1 of the well-nigh common mistakes of a homeowner is not checking its amperage. Some heater tanks merely have a label for their voltage and watt requirements but never their ampacity.

Information technology is best if you look for your tank specifications from the retailer or the brand manufacturer itself. Your heater must be your basis for determining the correct breaker size. To ensure safety, here are the three factors y'all should consider:

Voltage- The volts of your boiler plays an integral part in a good for you circuit. Yous tin can plug an boilerplate heater to a 220 or 240 Volts outlet based on your tank size and wattage.

Wattage- Accept your heater'due south wattage requirement into your list. Knowing its wattage is a great advantage if your device usually pulls an immense amount of power for its tank size and other features. Information technology will aid y'all search for a suitable breaker to handle it.

Wire Size- Lastly, it is essential to know what cablevision type is compatible with your hot water heater breaker size. An incompatible size or reused faulty wires tin cause more than take a chance than welfare for your heater and billow.

A Breaker Size Solution: What'south the Formula?

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If you're clueless near the amp size you'll utilize, doing a simple calculation is the answer. Since yous already know the wattage and voltage of your h2o heater, all y'all need is to follow the Ampere formula, which is I (amps) = P (watts)/ V (volts).

For example, I accept a heater tank of iii,000 watts that needs 120-volt power. To become its amperage, you lot need to split up your watts by volts.

Solution: I = P/Five

I = 3000 watts / 120 volts

I = 25 amps

Now you may be thinking, a device with 25 amps needs a billow size with the aforementioned value. Well, that'south where overloading and over-tripping get-go to happen.

At that place's a regulation ready by the National Electric Code (NEC) wherein you need to stay at 125% of the maximum continuous load. This footstep is vital to get the safe amount for your electric water heater breaker size.

For the example earlier, employ the continuous load dominion: 125% x 25 amps = 31.25 amps. And so, you lot can go the closest amp size which is 35 amps. For a 35-amp CB, the Foursquare D by Schneider Electrical HOM235CP is a highly suggested product.

If you have a xx-amps breaker defended to your 25A h2o heater, expect that your heater volition constantly trip it. Giving space for your billow will permit a power surge without tripping.

To meliorate sympathise, you tin can lookout this video from Business firm Wiring T.V.: correct way to size your h2o heater wires and Billow size!!!! – YouTube

What Size Breaker for 40 and lxxx-Gallon Water Heater?

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Most families employ a tank size of 40 to 80 gallons for a water heater — depending on how much they rely on warm water daily.

To find out how many amp breaker for water heater of these tank sizes, y'all'll demand their wattage and voltage, so employ the solution before.

For a forty-gallon heater, the average capacity is 4500 Watts with 240 Volts. Again, I = P/V; 4500W/240V = eighteen.75 amps. And then considering the continuous load (125% x 18.75A), nosotros'll get a total of 23.4 amps.

With our answer, a 40-gallon h2o heater needs at least a 25-amp breaker, the closest to the amperage value. Notwithstanding, I highly recommend using thirty-amps for a safer breaker size.

Meanwhile, an 80-gallon heater powered by 5500 watts and 240 volts, will result in 5500W/240V ten (1.25 continual load) = 28.64 amps. Meaning, a 30-amp defended circuit breaker is enough.

Pro-tip: Although a 30A billow sounds like it's non enough for an 80G tank, installing a 40A won't protect the device in case of an overload. A breaker amperage that's much higher than necessary won't trip when needed.

What's the Correct Wire Size for a Water Heater?

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The connection of a water heater to its breaker won't work well if the wiring is incompatible. Make certain that the amperage of your heater matches its wire size. You tin refer to this list:

20-amps = 12-approximate wire
25-amps = 10-gauge wire
thirty/40-amps = 8-gauge wire
Other large heaters up to 50-amps = 6-gauge wire

Too, consider your breaker size for h2o heater. thirty-amp excursion breakers, usually used for a large boiler tank, require a 10-2 not-metallic or MC cable. This type of wire is suitable for start loads of twoscore-amps and a constant load of 35-amps.

Preventive Measures Before Buying a Excursion Breaker

When choosing the right h2o heater circuit breaker size, you should exist frail about the amp difference between the breaker and the heater. You must get the right size. A breaker likewise large or besides little tin can risk an electrical risk.

If the breaker is too small for the water heater'southward ampere requirement, expect that your CB will trip continuously. Not only that, too much on and off of the heater can cause internal damage. Do non have your water heater share a circuit with other appliances, and delight upgrade the breaker if necessary.

A breaker with a higher amperage than intended doesn't immediately hateful that it's safer for the heater. If the tank all of a sudden has a curt circuit or overload, your breaker will disregard the effect — no protection at all.

Conclusion

Knowing what size breaker for a hot water heater is not that exhausting if you gather the correct data. Just by understanding the three wire heater elements — voltage, wattage, and wire size, you tin go the proper breaker size.

A elementary calculation volition also do the work, but go along the breaker size near the amount of your answer (the actual amp size of the heater).

An electric water heater typically uses a 30-amp breaker, and so something like the Q230 30-Amp Double Pole Type QP Circuit Billow volition practice the work well.

I am Andrew Wright. I established this blog after eight years of feel designing, installing, and maintaining electrical power systems. I love my task, and I take always wanted to offering others the necessary aid so they can take intendance of their houses.