What Size Breaker For A Water Heater

what size breaker for a hot water heater

Does your electrical h2o heater proceed tripping the breaker? Did your heater overload without discover? With simply these few questions, it is articulate that y'all're having a problem matching your appliance with its safety device.

What size breaker for a hot water heater, you say? The standard size for most heaters is 30-amps. Even so, this billow ampacity doesn't necessarily work for every water heater there is.

There is a formula for finding the right breaker size, but there are other essential factors to talk about later in this commodity.

Understanding Your Water Heater

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Upon purchasing an electrical water heater, ane of the virtually mutual mistakes of a homeowner is not checking its amperage. Some heater tanks only have a label for their voltage and watt requirements only never their ampacity.

It is best if you await 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, hither are the iii factors you should consider:

Voltage- The volts of your boiler plays an integral function in a healthy circuit. You can plug an average heater to a 220 or 240 Volts outlet based on your tank size and wattage.

Wattage- Take your heater's wattage requirement into your list. Knowing its wattage is a not bad advantage if your device usually pulls an immense amount of power for its tank size and other features. It will help y'all search for a suitable billow to handle it.

Wire Size- Lastly, information technology is essential to know what cable type is compatible with your hot water heater breaker size. An incompatible size or reused faulty wires can cause more hazard than welfare for your heater and breaker.

A Billow Size Solution: What's the Formula?

how-many-amp-breaker-for-water-heater

If you're clueless about the amp size you'll employ, doing a unproblematic calculation is the answer. Since you lot already know the wattage and voltage of your water heater, all you need is to follow the Ampere formula, which is I (amps) = P (watts)/ Five (volts).

For example, I accept a heater tank of 3,000 watts that needs 120-volt ability. To become its amperage, you demand to separate your watts by volts.

Solution: I = P/V

I = 3000 watts / 120 volts

I = 25 amps

Now you lot may be thinking, a device with 25 amps needs a breaker size with the same value. Well, that'southward where overloading and over-tripping start to happen.

There's a regulation set by the National Electric Code (NEC) wherein you lot need to stay at 125% of the maximum continuous load. This step is vital to become the safe corporeality for your electric water heater breaker size.

For the example earlier, apply the continuous load rule: 125% x 25 amps = 31.25 amps. Then, you lot can get the closest amp size which is 35 amps. For a 35-amp CB, the Square D by Schneider Electric HOM235CP is a highly suggested production.

If you lot accept a 20-amps billow dedicated to your 25A water heater, expect that your heater will constantly trip information technology. Giving space for your billow will allow a power surge without tripping.

To better understand, you can watch this video from House Wiring T.V.: correct way to size your water heater wires and Breaker size!!!! – YouTube

What Size Breaker for xl and 80-Gallon Water Heater?

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

To find out how many amp billow for h2o heater of these tank sizes, you lot'll need their wattage and voltage, then apply the solution earlier.

For a twoscore-gallon heater, the average capacity is 4500 Watts with 240 Volts. Again, I = P/V; 4500W/240V = 18.75 amps. Then considering the continuous load (125% ten 18.75A), we'll become a total of 23.4 amps.

With our answer, a 40-gallon water heater needs at to the lowest degree a 25-amp billow, the closest to the amperage value. Nonetheless, I highly recommend using 30-amps for a safer breaker size.

Meanwhile, an eighty-gallon heater powered past 5500 watts and 240 volts, volition result in 5500W/240V ten (i.25 continual load) = 28.64 amps. Meaning, a 30-amp dedicated circuit billow is enough.

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

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

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

20-amps = 12-approximate wire
25-amps = 10-gauge wire
30/40-amps = 8-gauge wire
Other big heaters upward to fifty-amps = 6-gauge wire

Too, consider your breaker size for h2o heater. xxx-amp circuit breakers, commonly used for a big boiler tank, require a 10-2 not-metallic or MC cable. This type of wire is suitable for showtime loads of 40-amps and a constant load of 35-amps.

Preventive Measures Earlier Buying a Circuit Billow

When choosing the right water heater circuit breaker size, you should be frail almost the amp deviation between the billow and the heater. You must get the right size. A breaker besides large or too little can risk an electric take chances.

If the breaker is likewise small for the water heater'due south ampere requirement, expect that your CB will trip continuously. Non only that, too much on and off of the heater tin can cause internal damage. Do not have your water heater share a circuit with other appliances, and please upgrade the breaker if necessary.

A billow with a higher amperage than intended doesn't immediately mean that it'southward safer for the heater. If the tank all of a sudden has a brusk excursion or overload, your billow volition condone the event — no protection at all.

Determination

Knowing what size billow for a hot h2o heater is not that exhausting if y'all gather the right information. But by understanding the three wire heater elements — voltage, wattage, and wire size, you can get the proper billow size.

A simple calculation volition also practice the work, but keep the breaker size most the amount of your answer (the actual amp size of the heater).

An electrical h2o heater typically uses a 30-amp billow, so something similar the Q230 30-Amp Double Pole Type QP Circuit Billow will do the work well.