Curious about the right breaker size for your hot water heater? Don’t fret; we’ve got you covered.
In this article, we’ll break down the process step by step, so you can ensure your water heater operates safely and efficiently.
No more guesswork—just clear guidance to make the right choice.
What Size Breaker For Hot Water Heater?
For a standard residential hot water heater, you’ll typically need a double pole 240-volt 30-amp or 50-amp circuit breaker. A 40-50 amp double pole breaker suits most 4500-5500 watt, 240-volt heaters.
Breaker size chart for hot water heater :
|Water Heater Power
Determining The Correct Breaker Size
There are some steps to figure out the right breaker size for your hot water heater.
Check The Heater’s Label
Begin by examining your hot water heater’s label. It’s like reading a book about your heater’s electrical needs. Look for details like voltage and wattage.
These numbers help you understand your heater better.
For instance, it might say: Voltage: 240 V Wattage: 4500 W
These numbers reveal that your heater operates at 240 volts and consumes 4500 watts of power.
Calculate The Ampere Rating
Calculate the ampere rating. This rating shows how much electric current your heater uses.
We can find it using a simple formula: Ampere Rating = Voltage / Wattage
For example, if your heater runs at 240 volts and 4500 watts: Ampere Rating = 240 / 4500 = 18.75
This means your heater draws 18.75 amps from the circuit.
Consider Voltage And Wattage
Finally, it’s time to make the right breaker choice. Follow these two rules:
Your breaker size should be at least 25% larger than the ampere rating of your heater. This adds a safety cushion.
Your breaker size shouldn’t exceed the circuit’s maximum capacity to prevent overloading and potential fire hazards.
For instance, if your heater’s ampere rating is 18.75 amps, you’d need a breaker size of at least 23.4375 amps (rounding up to 25 is fine).
But, check your circuit’s capacity too. If it’s 30 amps, a 30-amp breaker works well.
Types Of Circuit Breakers
There are two main types of circuit breakers that you can use for your hot water heater: single-pole breakers and double-pole breakers.
A single-pole breaker is a straightforward type that handles just one wire or phase within a circuit.
It boasts one switch and one terminal, making it suitable for circuits with a voltage of 120 volts or less. This type is commonly used in homes and many appliances.
The single-pole breaker is designed to disconnect power to only one side of the circuit when triggered.
This can be beneficial when a device needs to be powered down for maintenance or repair, leaving other parts of the circuit unaffected.
While single-pole breakers are versatile, they may not be suitable for larger appliances that require higher voltage, such as electric water heaters.
Conversely, a double-pole breaker controls two wires or phases within a circuit.
It features two switches and two terminals and is typically reserved for circuits with 240 volts or more.
Double-pole breakers are commonly found in larger appliances, like electric water heaters and air conditioning units.
When a double-pole breaker trips, it simultaneously disconnects both sides of the circuit.
This is crucial for safety in high-voltage applications, as it ensures complete power interruption.
Use double-pole breakers when necessary to prevent overload and potential damage to appliances or the electrical system.
Calculating Breaker Size
To ensure your water heater operates safely and efficiently, calculating the right breaker size is essential.
If you have an electric storage tank water heater with a voltage rating of 240 volts and a wattage of 5500 watts, follow these steps:
Step 1: Check the Specifications
Begin by checking your water heater’s label or manual for voltage and wattage details. In this case, it’s 240 V and 5500 W, respectively.
These numbers are crucial for calculating the ampere rating.
Step 2: Calculate Ampere Rating
Use the formula: Ampere Rating = Voltage / Wattage.
For our example, it’s 240 / 5500, resulting in approximately 22.92 amps of current that your water heater draws from the circuit.
Step 3: Select Breaker Type
Based on the voltage (240 volts), you’ll need a double-pole breaker. Determine the specific breaker size.
Step 4: Determine Breaker Size
Multiply the ampere rating by 1.25 to include a safety margin and round up to the nearest standard size.
For our example, it’s ⌈22.92 × 1.25⌉, which rounds up to 30 amps.
Step 5: Check Circuit Capacity
Ensure your circuit can handle the chosen breaker size.
If your circuit supports 30 amps or more, a 30-amp double-pole breaker is the right choice for your electric storage tank water heater.
Common Breaker Sizes For Different Water Heaters
Tankless Water Heaters
Tankless water heaters offer several advantages, including energy efficiency, endless hot water, and space-saving design.
They come with some drawbacks, such as higher installation costs, limited simultaneous usage, and potentially requiring a larger breaker size.
To calculate the breaker size for a tankless water heater, consider the voltage and wattage of its heating element.
Electric Storage Tank Water Heaters
Electric storage tank water heaters are known for being cost-effective, providing ample hot water, and not requiring gas or venting.
On the downside, they waste energy by continuously heating water and have a limited hot water supply.
To determine the breaker size for electric storage tank heaters, assess the voltage and wattage of the heating elements.
Gas Water Heaters
Gas water heaters are praised for their energy efficiency, rapid hot water recovery, and ability to operate during power outages.
They come with their own set of considerations, including the need for gas supply and venting, safety concerns, and potentially requiring a smaller breaker size.
Calculate the breaker size for gas water heaters by examining the voltage and wattage of their electric components.
FAQs about what size circuit breaker for hot water heater
Why are only double pole breakers used for hot water heaters?
240 volt circuits like those for most water heaters require a double pole breaker to disconnect both energized 120V hot wires with a single switch motion.
Can I use a higher amp breaker than the heater is rated for?
No, only use a breaker rated at or below the water heater amperage/wattage to prevent dangerous overheating from excess current.
What wire size goes with a 30 amp water heater breaker?
Use #10 AWG conductors on 30 amp circuits. For 50 amp breakers, #6 AWG wire is specified according to NEC minimums.
Do I need GFCI or AFCI breakers for hot water heater circuits?
No, GFIC and AFCI protection is not required by code for most hardwired water heating circuits.
Should the breaker be located close to the water heater?
Yes, locate the dedicated breaker as nearby as possible, within line of sight. This eases troubleshooting and access.
Determining the appropriate breaker size for your hot water heater is crucial for safety and efficiency.
By following the steps outlined in this guide, you can confidently select the right breaker size based on your water heater’s voltage and wattage.
Enjoy reliable and worry-free hot water in your home.