How to Turn Off Water Heater in Case of an Emergency

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Learning how to turn off your water heater is a great way to prepare for the worst. If you are ever in need of help, knowing about your water supply line could save you time and money. In this article, we will discuss how to shut down your water heater quickly and efficiently.

Let's get right into it.

How to turn off water heater

Turning off the water supply should be a top priority once you have determined that the water heater is in danger of catching fire.

The last thing you want to do is cut power when things have gotten worse as it can cause electric shocks or arc flashes which may start a gas leak along your gas supply line, so make sure your circuit breaker box has been shut off before shutting down anything else.

The gas supply is something we don't want to mess with as it can lead to gas leaks which are just about the worst thing you could experience, so we'll focus on how to turn off your water heater after turning off the gas.

Shutting down the power

The best way to proceed is by shutting down the power supply – also called a breaker or fuse box (this should be located outside of your home).

Once the supply valve is shut down, there will still remain some hot water in pipes and tanks for approximately 30 minutes before all heat dissipates. This means that if you're trying to get out quickly when an emergency strikes at home, this will give you enough time. The second step would then involve inspecting any gas line found near where the leak was detected and opening up window(s).

Gas water heaters are built with a device that shuts off gas automatically when the temperature drops below 20 degrees Celsius, so this should also be a good backup to keep in mind.

Size and frequency of use of your water heater

The size and how often you use your water heater also determines how long it'll stay on before shutting down (i.e., if you're using large quantities, like with multiple people or frequent showers, then this could mean more than 30 minutes).

As we mentioned, the first step will be turning off the main switch for both electricity and natural gas (if available) on the unit.

The water supply will also need to be turned off, which is usually located near the main water shutoff valve in your home. This means that everything will be turned off including your garden hose and drain faucet.

Replacing a tankless heater

If you have a tankless water heater and are replacing it with another of its kind, then this will mean being right there when they switch out so as not to lose power or gas while switching over.

The drain valve is also something that you should inspect for any potential problems (more on this later).

Thinking ahead in extreme weather conditions

In a case of extreme weather conditions, natural disaster, or another event that leaves you without access to water service, some steps can be taken to minimize damage before it occurs: turning off your hot water heater safely at least 24 hours ahead of time will save on electricity costs and allow you more time (and less worry) when dealing with how long each hot water tank lasts between draining cycles.

Also, checking the drain valve regularly ensures that no clogs occur during those times when there isn't enough clear flow out from the hot-water system.

When Should You Turn Off Your Water Supply?

Sometimes, the pilot light will come on and you will need to replace the thermostat in your hot water heater. In these cases, it might be better if a professional handles this for you so that there are no accidents and your system can be flushed before using it again.

Warning signs to keep in mind when it comes to your water heater

If you find any of the warning signs listed below, then it may be time to turn your water heater to the off position:

  • Strange noises coming from the outside vent pipe
  • A decrease in how quickly hot water flows through your water pipes (this may not apply with some types of heaters)
  • Hot or rusty water droplets on top of the water tank
  • Water leaks near an outlet valve or other drain point
  • Warm air blowing out from vents when the heating element should not be working
  • The pressure of the water heater drops below 20 psi

If you are in the process of installing a new water heater, or if you believe your system is malfunctioning and needs to be replaced immediately, then it may also be a good time to shut off the power. Leaking water heater? Turn it off as well and contact a professional plumber.

Gas water heater vs electric water heater

Turning off both a gas water heater as well as an electric heater water heater is fairly easy.

A gas water heater will need the shut-off valve to be closed completely, while an electric water heater only needs a breaker to be turned off at the main panel outside of your home.

If there are no lights or the pilot light is off and you believe that it shouldn't be, it's important to check that the pilot light is functioning correctly before shutting anything down.


Some safety tips when it comes to water supply

A gas supply line is live even if the gas is turned off. If you smell natural gas, turn off the gas and any potential sources of ignition and immediately call your gas company as well as the local fire department for help.

The shutdown procedure varies by the manufacturer so refer to installation instructions for how to do this safely.

To test it out first, remove the wires from their terminal screws at the bottom of the electric panel then reconnect them after turning the power back on. This will cause an interruption in power without actually shutting things down.

Your whole house is at risk in the case of a power outage. If you know this is going to happen, learning how to turn off your water heater to prevent potential damage or scalding accidents important.

Such accidents caused by a water heater put your entire house at less risk.

Hot water faucet and valves

You can also take the opportunity now while we're still talking about faucets and valves to learn about how to turn on and off your gas valve.

Valves to know about

A pressure relief valve will ensure that if there is too much pressure and the tank gets too hot, it will release some of the gas so it doesn't explode.

There's a knob or lever on top of most water heaters to turn on and off this valve – please note how yours looks before an emergency hits.

Some water heaters also have two valves including a ball valve.

To turn off a ball valve, you will have to unscrew the locknut.

Typically this is how faucets are turned on and off with valves in case there's no hot water.

You can also use pliers to tighten or loosen the lock nut depending on how tight it needs to be for the pressure relief valve.

If your gas line should leak or break, never approach it without turning off all other sources of natural gas including ovens, stoves, fireplaces, and so forth first.

Dealing with a leaking water heater

If you experience a water leak coming from your water heater, you will need to shut off the gas and power to it.

Shutting off the power first is typically how people deal with a leaking water heater because they don't want any electric shock or electrocution hazards that could occur if someone accidentally comes into contact with live wires.


Other household appliances to consider

Next, turn off all other sources of natural gas including ovens, stoves, and fireplace so as not to have anything else near them before shutting down the rest of the necessary equipment.

After turning off the main valve, you'll want to turn off any valves that are connected to it such as ones for sinks and toilets.

Final thoughts on electric water heaters and gas water heaters

Turning your heater off in the case of an emergency is not difficult, but you do want to make sure that someone can shut it off if necessary.

In an emergency like a gas leak or the power going out, shutting down your water heater will help ensure safety for all those involved in the event.

Dino Paccino

Dino Paccino

Dino is a lifelong writer and home improvement specialist. He enjoys bringing cutting-edge information on home renovation and remodeling to Kitchen Infinity.

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