Will a Gas Water Heater Work Without Electricity?

We’ve all had power outages at the most inconvenient times. They’re seldom convenient, and they almost always result in increased stress. Many people have wondered, will a gas water heater work without electricity. A simple response is that it depends on numerous factors that will be discussed in this article.

Different types of water heaters are classified according to their fuel source and efficiency. So whether you can still have a lengthy, excellent shower in the dark depends on the sort of water heater in your home or if you’ll have to settle for dull cold water until the electricity comes back on. [1]

So, will a gas water heater work without electricity?

Anything that relies only on electricity will not function after a power outage. However, gas-powered water heaters will continue to work and heat your water because the gas is not attached to your electric system. The various water heaters that rely on different fuel sources are listed below.

Types of Water Heaters

rheem water heater

  • Electric conventional tank water heater

If you have an electric-powered tank-style water heater, your water heater will stop heating water if there is a power outage. However, water that has already been heated to the point where the power cuts out will stay hot in the insulated tank for an extended period. To keep the remaining hot water as hot as possible while the power is off, cut off the water and power supply to the tank water heater. This supply of hot water could last a few days. [2]

  • Gas conventional tank water heater

Because gas water heaters do not require electricity as a fuel, many homeowners believe they will function in case there is a blackout. This is dependent on the sort of gas water heater you have. In the event of a power loss, if your gas water heater uses a continuous gas pilot light, it will likely continue to operate regularly. Because they are not reliant on mains electricity, even gas water heaters with electric pilot lights can work.

If you discover a power connection linked into the wall and attached to your gas water heater, it is likely powered by the mains and will only provide hot water for a few days if there is a power outage (the same as an electric tank). If this is the case, ensure that your gas supply is turned off in the event of a power loss.

  • On-demand electric water heater

Since an electric on-demand water heater requires energy to heat water on the spot for immediate use, your on-demand electrical water heater will not produce any hot water during a power outage.

  • On-demand gas water heater

While on-demand propane water heaters do not use electricity to heat water, they do feature an electrically powered control panel that serves as the water heater’s “brains.” As a result, even a tankless gas water heater will not function in a power loss.

  • Other types of water heaters (solar, fuel oil, heat coil, indirect)

Your water heater’s ability to function during a power outage is determined by whether it is powered by mains electricity or not. The simplest method to ensure this is to check if the water heater is connected to a power outlet. If power failure is a concern in your home, you should choose your water heater carefully.

What Is a Gas Water Heater?

Gas water heaters have a constantly burning pilot light and should function in a power loss. The gas water heater is wired with electricity to provide the spark that ignites the pilot light. On the other hand, the pilot light will burn once it is lit. As a result, the gas water heater does not require power to function correctly.

How does a gas water heater work


The tank-type water heater heats cold water and then stores it until various plumbing fittings require it throughout the house. Convection is the physical law that governs how heat rises in a gas water heater.[3]

A cold water supply tube brings cold water into the tank. A gas burner positioned underneath the sealed tank heats the thick cold water at the bottom of the tank. As the water warms, it rises in the tank, where the hot water outlet line draws it away to deliver hot water wherever needed.

Because the hot water discharge pipe aims to funnel off the hottest water, which is found at the apex of the tank, it is much shorter than the dip tube.

A gas regulator component installed on the side of the water heater controls the gas burner that heats the water. In addition, it includes a thermostat for checking water temperature. It also switches the burner on and off as needed to keep the water at the specified temperature.

An exhaust flue sits at the center of the tank, allowing exhaust gases to escape through the chimney. In addition, a spiral metal baffle is installed in the hollow duct to optimize the appliance’s effectiveness, collecting heat and transmitting it to the surrounding water.

Electrical requirements for gas water heater 

Tankless water heaters are highly efficient when compared to typical water heaters. Even if a gas tankless unit runs on propane, several sections of the water heating system still rely on electricity. So, what does a tankless gas water heater demand in terms of electricity?

The National Electrical Code recommends that tankless gas water heaters have a 15-20 ampere 120-volt electrical connection to power the control board and ignition mechanism. The circuit breaker setting determines the circuit ratings because the control circuit is an independent load.

An electrical control circuit of a propane tankless water heater guarantees that the control board gets enough power. In addition, the control board detects the temperature of the water fed to the tankless unit as well as the water that exits the water heater and enters the home’s faucets.

The operation of control boards necessitates the use of power. The control board can adjust the amount of heat necessary to heat water to the desired temperature when powered adequately according to the NEC code.

After determining the desired temperature, the control board starts an electronic ignition sequence that heats the water to the specified temperature and delivers it to the point of demand in residence.

The circuit size will have been calculated and set by the manufacturer, whether you’re using a Rheem, Ecosmart,Takagi or Rinnai tankless natural gas water heater. Rinnai tankless water heaters, for example, require 120 volts AC, 60 Hz, and less than three amps of electricity.

The units typically come with detailed installation instructions to assist you or your technician in completing the job correctly.

Gas water heater electrical connection 

Most homeowners believe that a gas water heater can operate in a power loss. Although the tankless unit does not need electricity to heat the water, it may rely on some electric components to function efficiently. Your gas water electrical connection consists of the electric components outlined below: 

Electric control board

A tankless gas water heater’s electric control board is a crucial component. Information is relayed, and electric control boards monitor communication between all electrical components in a series circuit. This is what enables smooth operation with no interruptions or failures.

The water heating system’s electric control board is similar to a computer. The water heater is powered by electricity, which is why your gas instantaneous water heater might not work if there is a power outage.

The electric control board detects the temperature of the water coming into the tankless unit and tells the burners to switch on or off based on the temperature. In a nutshell, this circuit board regulates the gas valve, burner, and water temperature. This is how your home’s hot water is delivered on-demand.

Gas pilot light

In some types of any propane or gas hot water system, a gas pilot light is an essential part of the gas safety mechanism. The pilot light is a little flame maintained lit in your water heating system. In some cases you heater may keep turning off all the time.

The electric control board is in charge of the gas pilot light. If water needs to be heated, the pilot light is activated, igniting the burners and raising the water temperature to the level set by the control unit.

Keep in mind that tankless gas water heaters warm water almost on demand, which means they use less energy than tank-style water heaters, which use more power to keep water at the same temperature all day.

Do Rheem gas water heaters need electricity? 

Despite the fact that there are more sophisticated forms of water heaters on the market, the commonest kind available in the United States is the dependable gas water heater. Most of these machines make use of heat rises and consist of a big water-filled drum with a heating mechanism attached.

A gas water heater will provide hot water whenever you need it. These water heaters strike the right blend of efficiency and performance to suit your family’s budget and hot water requirements. Rheem offers numerous gas-powered solutions if you don’t want a traditional tank-type water heater.

  • Tank water heaters that are standard. This is the most cost-effective option upfront, but it will save the least energy after installation.
  • Water heaters that are Energy Star certified. These gas water heaters include electric ignition pilot lights, are more energy-efficient, and save a lot of money.
  • Tankless water heaters. This space-saving model heats water on demand and is the most energy-efficient gas-powered water heater available.

How to turn on water heater without electricity?


Is it possible to use a tankless gas water heater without electricity? No, a tankless gas water heater still needs the power to function. Tankless gas water heaters use energy to power an internal PC board, electronic ignition, and an electronic thermostat.

These components will not work without power, stopping the tankless water heater from producing hot water.

A built-in PC board and digital remote operate tankless water heaters, which require power to operate. These components detect water flow and activate the burner to provide hot water on demand.

A direct electric ignition system, which uses 120v power to light the burners as hot water is required, is also included in tankless water heaters. However, the ignition system will not work if the electricity goes out.

While your gas-powered tankless water heater does require electricity to operate, it does not have to come from your home’s electrical socket. Instead, a portable generator is ideal if you encounter a power outage. The generator can be used in powering the tankless water heater.

It might also prove handy in supplying other household appliances and mechanicals such as the heating and cooling system, refrigerator, stove, lights with power.

A battery-powered backup system can be added to give interim power to the tankless water heater if a backup generator is not an option.

So, will a gas water heater work without electricity?

Turn off the power to your gas heater if there is a power outage. When the electricity is restored, voltage fluctuations may cause harm to your appliances. After fixing the electricity, you can turn on your gas heater and other devices.

Gas heaters with a gas pilot light will continue to operate without electricity. Depending on the size, position, and insulation of the electric heater, it can keep the water heated for several hours or days. However, if your neighborhood experiences extended periods of power outages, you may want to consider installing a generator to power your home.