Gas vs. Electric Water Heater: Which Is Right for You?
The one big difference you'll notice right away between gas and electric water heaters is how they heat your water. Gas models generally recover faster and are able to operate during an outage if they don’t need electricity, while electric models generally have a lower initial cost and can be more efficient. The best option usually depends on your home’s infrastructure, your hot water needs, and how often you experience power outages. Here’s how gas vs. electric water heaters stack up, including cost, efficiency and what happens when the power goes out.
The Basic Difference Between Gas and Electric Water Heaters
The main difference between gas and electric water heaters is how they generate heat. Gas models have a burner to burn natural gas or propane. Electric models have heating elements inside the tank. That difference affects the installation, heating speed, energy use, and how each heater performs during a power outage.
How Each Type Actually Heats Water
Electric water heaters contain heating elements that heat water directly in the tank. A gas model uses a burner at the bottom of the tank to burn either natural gas or propane and transfer that heat to the water. Gas units also need to be vented properly, whereas electric models don’t need a gas line or combustion vent.
Tank vs. Tankless Applies to Both Types
Both gas and electric water heaters come in tank and tankless versions, so the fuel choice is separate from the tank decision. A traditional tank keeps a supply of hot water ready, while a tankless unit heats water as you use it. Tankless models take up less space and don't have to keep a full tank hot between uses, but they usually cost more to install.
Gas Water Heaters: Pros and Cons
Gas water heaters are a common choice for homes that already have natural gas service. They can heat water quickly and recover faster after heavy use, but they usually cost more to install and maintain than electric models.
Faster Recovery and Works During Some Outages
Gas water heaters generally recover faster than electric models, which can be useful for larger households that go through a lot of hot water. Some older tank models with standing pilot lights can also keep heating water during a power outage because the pilot doesn't rely on household electricity. Modern gas models are different. Tankless units, power-vented tanks, and models with electronic ignition typically need electricity for their controls, igniters, or exhaust fans. If outages are a regular concern, a home battery backup can help keep an electric-dependent gas water heater running.
Higher Upfront and Maintenance Costs
Gas water heaters often cost more to install because they may need a gas line, proper venting, and additional safety work. That can make the upfront price much higher if your home doesn't already have gas service. They also need regular maintenance, including checking gas connections and keeping the burner and ignition components in good working order.
Electric Water Heaters: Pros and Cons
Electric water heaters are often easier to install and cost less upfront than gas models, especially in homes that don't already have a gas line. They also avoid the need for combustion and gas venting. The trade-off is that they generally heat and recover more slowly, and a standard electric unit can't heat water when the power is out.
Lower Upfront Cost and Safer Operation
Electric water heaters are typically cheaper to buy and install because they don't need a gas line, burner, or exhaust vent. If your home already has the right electrical service, installation can be fairly straightforward. Since the heater doesn't burn fuel, there's also no combustion or carbon monoxide risk from the unit itself.
Slower Heating and No Power, No Hot Water
Electric resistance models usually take longer to heat water and recover after the tank has been heavily used. That may be noticeable in larger households where several people need hot water around the same time. There's also a more immediate issue during a blackout: a standard electric water heater stops heating as soon as the power goes out, so you'll need the grid or a suitable backup power source to get hot water again.
Which Is More Efficient, Gas or Electric?
Electric water heaters generally have higher efficiency ratings than standard gas models, but that doesn't automatically make them cheaper to run. Your local electricity and natural gas rates, the type of heater, and how much hot water your household uses all affect the actual cost.
Comparing Energy Factor Ratings
The Department of Energy uses the Uniform Energy Factor (UEF) to measure water heater efficiency. Standard electric resistance storage water heaters typically have UEF ratings of 0.90 to 0.95, compared with roughly 0.55 to 0.70 for standard gas storage models. Electric heat pump water heaters can reach UEF ratings of 3.3 to 4.1 because they move heat from the surrounding air instead of generating it directly.
Efficiency Doesn't Always Mean Lower Bills
A higher UEF doesn't necessarily mean a lower monthly bill because electricity and natural gas prices vary widely by location. The California Energy Commission recommends comparing UEF ratings within the same usage bin and fuel type rather than treating UEF as a direct gas-versus-electric comparison. So while electric models can look more efficient on paper, your local utility rates still matter when choosing the better option for your home.
Efficiency is only part of the decision, though. When the power goes out, a standard electric water heater stops heating, which can leave you without hot water once the tank cools. If you want to keep hot water available during a blackout, the next step is figuring out what kind of backup power can handle the heater's electrical load.
Keeping an Electric Water Heater Running During an Outage
A standard electric water heater stops heating when the power goes out. A battery backup can keep it running during an outage, as long as the system has enough output for the heater and enough battery capacity for the expected runtime. The right setup depends on what you need to power: a whole home with an electric water heater or a smaller setup with a point-of-use heater and a few essential devices.
Whole-Home Backup for Electric Water Heaters and More
A whole-home battery can handle the high power demand of an electric water heater while also keeping other essential circuits running during an extended outage. For homes that want backup power beyond hot water, a system such as the EcoFlow DELTA Pro Ultra X provides a larger-scale option.
Portable Backup for Smaller Electric or Point-of-Use Heaters
A portable power station can be a practical option for a smaller point-of-use electric water heater. It can also keep essential devices running during an outage when you don't need whole-home backup.
The outage question is only part of the decision. The better choice depends on your home's existing setup, hot water needs, and how you want to handle power outages.
Which One Should You Choose?
Go With Gas If
Gas may be the better fit if your home already has a gas line and proper venting, especially if your household uses a lot of hot water. It's also worth considering if you live in an area with frequent or extended power outages and have a gas model that can operate without household electricity.
Go With Electric If
Electric may make more sense if your home does not have existing gas infrastructure and you want a lower upfront cost and simpler installation. It is also a good fit if you already have, or plan to add, a battery backup for home to keep the water heater running during outages.
Conclusion
The choice of a gas or electric water heater depends on the layout of your home, your hot water needs, energy rates and the frequency of power outages. Gas units might bounce back faster and keep running during a power outage because they don’t require electricity, while electric models typically cost less to buy upfront, are simpler to install and boast better efficiency ratings. Before you make a decision, make sure to check whether your home already has a gas line, and compare UEF ratings for the same fuel type. If you go with an electric water heater and have frequent power outages, a battery backup can keep it running when the grid goes down.
FAQs
Is it cheaper to run a gas or electric water heater?
That will depend on what kind of water heater you have and on your local utility rates. Gas can be cheaper to run, where natural gas is cheaper. Electric models often use energy more efficiently. Compare your local electricity and gas prices along with the heater's efficiency before deciding.
Do electric water heaters work during a power outage?
No. A regular electric water heater requires electricity to heat the water, so it will cease heating when the power goes out. A battery backup can keep it running during an outage if the system can handle the heater's power demand and provide enough capacity for the runtime you need.
Which is more efficient, a gas or electric tankless water heater?
Electric tankless water heaters are generally more efficient than gas tankless models because they don't lose energy through combustion and exhaust. Gas models can still make sense if your home already has gas service or doesn't have enough electrical capacity for an electric tankless unit.
Is it worth switching from electric to gas, or gas to electric?
You might want to make a switch if you need a new water heater or if the energy situation in your home has changed. If you don't have gas service already, electric might be the easier route, but gas can be a good choice if your house already has the required gas line and venting. Compare the installation cost and expected energy costs before making the switch.
How can I keep an electric water heater running during a blackout?
You will need a battery backup that is enough to meet the power requirement of the water heater and also enough stored energy for the outage. A whole-home battery can run the water heater along with other essential circuits, while a portable power station may be suitable for a smaller point-of-use heater or other limited loads.
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