What is the Hot Water Tank Breaker Size? Most hot water tanks come with a 15 or 20 amp breaker. But is that the right size breaker for your tank?
A too-small breaker can overload and trip, leaving you without hot water. A too-large breaker can waste energy and money. So what’s the right size breaker for your tank? Let’s take a look.
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4500 Watt Hot Water Heater Breaker Size
A 4500 watt (maximum) electric water heater needs a 40 or 50 amp breaker. That’s the standard for most homes in the United States.
Electric Water Heater Breaker Size Example
If you had an 8-gallon hot water tank that drew 2200 watts, it would need at least two 20 amp breakers. That would be a total of 4400 watts, which exceeds the 4500-watt maximum by 100 watts.
Electric Water Heater Breaker Size Example
If you had an 8-gallon hot water tank that drew 1500 watts, it would need at least a 20 amp breaker. That will still leave you with a little breathing room if your hot water usage rises later on down the road. At 2200 watts per hour, it would take less than three hours to go through 8 gallons of hot water when using a 1500 watt system.
A Gas Hot Water Tank Breaker Size
As with electric systems, gas systems come in all shapes and sizes, so there is no hard and fast rule for what size breaker they require. But there are some general guidelines to follow:
Tank Size & Wattage Breaker Size
A typical 40-gallon hot water tank that draws 40,000 BTUs needs a 60 amp gas line. A 50-gallon tank with a higher efficiency burner might only need a 45 amp gas line even though the total BTU output is greater.
Incorrect Gas Line Size Example
If you have a 50-gallon gas system with an 80,000 BTU/Hr input and you install a 30 amp breaker, it will overload as soon as you turn on your main bathroom shower and then trip off. You will end up waiting around for 15-20 minutes for the breaker to re-set so that you can take your second shower after work—an inconvenience at best, but at worst, a safety hazard.
Correct Gas Line Size Example
If you have a 50-gallon gas system with an 80,000 BTU/Hr input and you install a 60 amp breaker, it will not overload no matter how many showers everyone takes after work before your husband gets home and turns on the dishwasher (or attempts to).
Tank Size & Wattage Breaker Size
A typical 40-gallon hot water tank that draws 40,000 BTUs needs a 60 amp gas line. A 50-gallon tank with a higher efficiency burner might only need a 45 amp gas line even though the total BTU output is greater.
What Size Breaker Should A Hot Water Tank Be On?
As always, check your local building codes to ensure you comply. But for most residential homes in the United States, a breaker size between 40-50 amps will work on either an electric or gas water heater within reason (see above). Call a qualified plumber if you have any doubts about what size breaker is right for your tank.
Electric Water Heater Breaker Size Example
If you had an 8-gallon hot water tank that drew 2200 watts, it would need at least two 20 amp breakers. That would be a total of 4400 watts, which exceeds the 4500-watt maximum by 100 watts.
What Size Breaker Do I Need For A 40-Gallon Water Heater?
Most water heaters of this size come equipped with a 40 amp breaker. If you suspect that your 40-gallon hot water system needs a different size breaker than what came with it, consult a licensed plumber before making the change.
A Gas Hot Water Tank Breaker Size
As with electric systems, gas systems come in all shapes and sizes, so there is no hard and fast rule for what size breaker they require. But there are some general guidelines to follow:
What Size Breaker Should I Use On My Hot Water Tank?
If you’re looking at your home’s electrical panel and wondering how big of a breaker you need for your tank, here is some background information on how many amps/breakers most residential water heaters use.
For a standard 40-gallon gas water heater, you would need a 60 amp breaker if your washer and dryer are located in the same room as your heater. If they are not, you would need a 45 amp breaker to supply sufficient power to the water heater.
If you aren’t sure of the breaker size required for your tank, consult a qualified plumber before changing anything.
What Size Breaker Do I Need For A 50 Gallon Water Heater?
The typical 50-gallon gas water heater comes with a 60 amp breaker. That does not mean you need to have a 60 amp breaker in your electrical panel if you have the standard 50-gallon water heater. Again, consult a licensed plumber before making any changes to ensure that you comply with your local building codes.
What Size Wire And Breaker Do I Need For A Hot Water Heater?
When installing a new tank, it’s important to use the right wire and breaker in order to ensure that the system has enough power.
For most residential electric water heaters, a minimum of 10-3 wires is required with a 30 amp breaker in the panel.
A minimum of 10-1/0 wire is required for most gas water heaters with a 60 amp breaker.
Final Verdict
How big a breaker you need to install your hot water tank safely is determined by how much amperage it can handle.
Your electrician will be able to recommend a reliable breaker that’s compatible with your home’s electrical system.
It is also a good idea to ask them for recommendations for installing an exterior disconnect switch to keep yourself and others safe from electrocution when working around electricity near the power box outside of your house.
