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How to Turn off Water Heater Power [Step-by-Step Guide]

How to Turn off Water Heater Power [Step-by-Step Guide]

Turning off the water heater is something every homeowner and renter should learn how to do. It’s a simple process, but it can be dangerous if done incorrectly or if you skip a step.

If you want to know how to turn off water heater power, you’re in the right place. That’s today’s homeowner lesson! With that said, let’s dive in.

Reasons to Turn off a Water Heater

Reasons to turn off water heater power listed in list form next to a graphic of a person turning off a water heater

You might need to turn your water heater off for several reasons. Some of the most common are: 

  • You hear strange noises coming from the water heater
  • The water heater is overheating
  • You’re running out of hot water too quickly
  • There’s no hot water in the house
  • There’s a problem with one of the water heater components
  • You want to drain the water heater tank to clean it
  • You’ll be away from home for a while
  • You see the water heater leaking
  • The main water supply is turned off

Basically, anytime the water heater will be worked on or inspected due to an issue, it should be turned off.

If there’s no water to refill the tank (if the main water supply is turned off), the water heater should be turned off to prevent excess heat or pressure from building up inside the tank. 

Vacation Mode

It’s a common misconception that water heaters should be turned off when you go on vacation. Sure, you don’t want to waste money heating water while you’re away from home.

But the energy savings you’ll get from turning it off completely for a few days are pretty negligible. If you’re taking a vacation during the summer (or if there’s no danger of your pipes freezing while you’re away), you can turn your water heater off.

But be aware that it might use even more energy to reheat the entire tank of water once you turn it back on. A better solution for vacations is to use your water heater’s vacation mode.

Not all models have this, but most newer water heaters do. Some even allow you to program your return date so you won’t need to switch the water heater back into its regular operation mode. 

Simply turn the dial on the water heater to the setting labeled “VAC” or “VACATION.” If you don’t have a vacation setting, just lower the thermostat to its lowest setting for the duration of the time you’re away. 

How to Turn off Water Heater Power

Whatever your reason is, turning your water heater off is a simple process. Below are step-by-step instructions for turning off a water heater.

We’ve included specific instructions for different types of water heaters, so scroll down to find the right type. Before getting started, please note that water heaters can be dangerous appliances to work on.

They are connected to either natural gas, propane, or dangerous electrical current. Misuse or mistakes during the process of turning a water heater off or on can potentially be fatal.

If you feel uncomfortable or have trouble with any of the following steps, stop what you’re doing and call a professional. 

How to Turn off Gas Water Heater

Infographic showing you how to turn off a gas water heater

  1. Locate the water heater. It’s usually in a utility closet, garage, or attic. You may find yours in the basement if you have one.
  2. Look for the temperature dial on the tank. It should be near the bottom of the tank on the front side. Turn the dial to the Off position.
  3. Find the water line that connects to the water heater. This will usually be located at the top of the water heater. You’ll see a valve on this plumbing line. Turn it off to stop the water supply that normally flows into the tank.
  4. Look for the natural gas line that connects to your water heater. It’s usually installed right next to the water heater. The gas line will also have a valve.
  5. To turn off the gas supply, turn the valve lever to a perpendicular position (so it’s at a right angle to the gas line).

If yours has a knob instead of a lever, turn the knob clockwise to shut off the supply. The knob should be labeled to show where the Off position is.

How to Relight the Pilot Light

Turning off your gas water heater and cutting the gas supply means the pilot light will no longer be lit. When you’re ready to turn a gas water heater back on, follow these steps to ensure you’ve done it properly:

  1. With the gas supply still shut off, look for the pilot light access on your water heater. It will be located under the gas valve. Your water heater’s pilot light access might be an opening, or it may be covered.
  2. Bend down (we recommend using a headlamp for better visibility) and look for the two small gas tubes inside. Keep an eye on these as you work.
  3. Turn the gas knob to the Pilot setting, or look for the red button that starts Pilot mode. Press and hold the knob or button down to start the gas flow that will enable you to light the pilot light.
  4. While holding the pilot knob or button-down, ignite the pilot light.
  5. Your water heater might have an ignition button (usually black) that you can press to ignite the pilot light. In this case, press the black button while continuing to hold the Pilot knob or button-down.
  6. Keep holding the gas button for one minute, then slowly release it and check to ensure the pilot light stays lit.

If your water heater doesn’t have an ignition button, you’ll need to use a long lighter to light the pilot light. Be very careful.

  1. While holding the gas knob down, position the tip of the lighter into the pilot light area where the two small gas tubes are.
  2. Ignite the pilot light and immediately remove the lighter from the area while holding the gas knob down for one minute.
  3. Slowly release the knob and make sure the pilot light stays lit. Once you see that the pilot light is lit and hasn’t gone out, you can turn the gas knob to the On setting.
  4. You’ll hear a clear whoosh or whump sound as the main burner ignites.
  5. Turn the water supply back on at the top of the tank, and you’re good to go. 

How to Turn off Electric Water Heater

infographic listing the steps about how to turn off an electric water heater

To turn off an electric water heater, locate the water heater (usually in a utility closet, garage, attic, or basement) and follow these steps in order:

  1. First, look for the breaker box panel in your home. It will have lots of circuit breaker switches inside.
  2. Look for the switch that connects to your water heater. It should be labeled.
  3. If it’s not, go ahead and label it now. The breaker switch for an electric water heater will be a double pole switch. It will look twice as wide as the single-pole switches in the breaker panel.
  4. Once you’ve located the water heater breaker switch, move it into the Off position. You will hear it click as you turn it off. Make sure the power is off on your electric water heater before proceeding.
  5. Tell any other household members what you are doing and make sure everyone knows not to touch the breaker panel while you’re working.
  6. Next, with the water heater power turned off at the breaker, turn off the tank’s water supply.
  7. Look near or at the top of the tank for the water supply line and its valve. Turn the valve off. You’ve now cut the power supply and the water supply to the water heater.

If you plan on making any type of repair, draining and flushing the tank, or replacing a part, make sure you allow the water inside the tank to cool sufficiently first. The water is hot enough to scald you. 

How to Turn on Electric Water Heater

When you’re ready to turn your electric water heater back on, it’s easy to do so:

  1. First, turn the cold water supply back on by adjusting the valve you turned off.
  2. Next, go to the breaker panel and locate the water heater breaker switch. It should still be in the Off position.
  3. Move it into the On position.
  4. Go to the water heater and listen for any low sounds that indicate it is on and working.

You should have hot water again within an hour or so.

How to Turn off Gas Tankless Water Heater

A graphic illustrating the steps to turning off a gas tankless water heater

Gas tankless water heaters use natural gas as a power source, but they also use electricity to power the control panel and igniter.

Be extremely cautious to ensure both the electrical current and gas supply are turned off to the unit.

  1. Locate the circuit breaker that supplies current to your gas tankless water heater.
  2. If your water heater has a control panel button that allows you to turn it off there, you can use that. However, it’s always a good idea to turn the power off at the breaker.
  3. Look for the gas valve connected to the water heater
  4. Adjust the valve clockwise to shut off the gas supply.
  5. Wait at least 5 minutes to allow any remaining gas to clear. (If you smell gas after 5 minutes, leave the house and anyone else in the home and call the gas company right away).
  6. Next, you’ll shut off the water supply to the tankless unit. There are three water valves that connect to a tankless water heater (cold, hot, and primary). Close, or turn off, all three valves. 

How to Turn on Gas Tankless Water Heater

When you’re ready to turn your gas tankless water heater back on, follow these steps in order:

  1. First, flip the correct breaker switch back to the On position.
  2. Next, double-check the temperature your tankless water heater is set to. Most models have a digital screen that allows you to set the temperature.
  3. Finally, turn the three water supply valves and gas supply back on.
  4. Turn on the hot water tap at the faucet furthest from the water heater to purge any trapped air from your plumbing. 

How to Turn off Electric Tankless Water Heater

An infographic showing the steps to turning off an electric tankless water heater

To turn off an electric tankless water heater with no natural gas supply, follow these steps in order:

  1. Locate the circuit breaker panel and identify the switch that corresponds to the tankless water heater.
  2. You can also use the control panel on the unit if there is one present, but it’s better to do this directly at the breaker.
  3. Make sure the power is off by turning on hot water faucets and ensuring the water is not being heated.
  4. Once the power is off to the unit, close the three water valves connected to the tankless water heater (cold, hot, and primary).

How to Turn on Electric Tankless Water Heater

To turn an electric tankless water heater back on, follow these steps in order:

  1. Go to the breaker panel and flip the water heater’s breaker switch back into the On position.
  2. Turn the water supply valves for all three lines back on to allow water into and out of the tankless water heater.
  3. Make sure the water heater is set to your preferred temperature once it is back on. 
  4. Turn on a hot water tap at the faucet furthest from the water heater to purge any trapped air from the system.

You can test it to ensure the unit is working properly and heating water. 

When to Turn off Water Heater Power

Now you know how to turn off water heater power for gas, electric, and tankless units. When should you do this? At the start of this guide, we talked about some common reasons for turning off a water heater.

Anytime you perform maintenance, do a repair, or suspect a problem with your water heater, you need to turn it off.

For gas water heaters, it is essential to shut off the gas supply and the water supply. For electric water heaters, make sure the water heater is turned off at the breaker, then cut the water supply. 

For tankless water heaters, remember that gas tankless water heaters are also connected to an electrical current to power the control panel and igniter.

You must shut the electrical power off at the breaker and ensure you also cut off the gas supply for these models. 

Knowing how to turn off your water heater will help you maintain it and feel confident anytime you need to shut it off in the future.

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