Water Heater Turned on Without Water [3 Possible Dangers]

Do you know what can happen if the water heater turned on without water? It can bring a disaster for your family.

That’s the reason, for your safety, today will discuss risk factors, the required issues, and what preventive measures you can take in case of your gas water heater is turned on without water.

To comprehend the whole factor and keep your water heater trouble-free, first, you should know how a water heater works. So, let’s first explore this topic…

How Does the Water Heater Work?

We use two types of water heaters in our house. There are gas water heaters and electric water heaters which are very effective in our daily use. Both of them provide a hot water supply to your bathroom and you have a refreshing bath. But, what’s the process, how do they work?

You should know the working process if you wish to know what dangers can happen if a water heater is turned on without water. 

Electric Water Heater

These water heaters are attached to our washroom. In this stage, we will share some tips that will keep you safe. There are two types of water tanks, tankless and with tanks. The electric water system keeps the water hot and supplied on time. 

An electric water heater with a tank has an automatic sensor that tells the inside water is cold. It comes through the dip tube into the tank and starts to heat it after turning it on. When we use the hot water, the water level comes down and it is filled again with the dip tube. 

On the other hand, there is another type of heater without any tank. It is attached to the water supply line and heats the supply pipe before water delivery. It is a very effective and advanced system where it gives instant hot water. It is safer and smarter. 

Gas Water Heater

In the case of using these heaters, there are gas burners attached to the tank or the water supply line. Here you will see the gas burner is controlled by a sensor. When we turn on the system, the gas burner is lit and delivers hot water. 

On the other hand, when we look for an instant hot water supply, it heats the supply pipe and delivers hot water instantly. This system comes with both sensor and without-sensor versions. Gas water heaters turned on without water can even explode! So be very careful.

When we use these systems, we should be careful if they do not have any sensors. In this stage, we will share some excellent tips that will keep you safe from accidents. 

Water Heater Turned on Without Water [3 Possible Dangers]

There are two types of water heaters, gas water heaters, and electric water heaters. Both of these are run by either electricity or gas; so they could be dangerous if not maintained properly. So, we will see what the level of danger is here. 

Danger 1:

In the case of electric water heaters, the tank-based model has a sensor that fills the tank when it is empty. When we use the hot water and the tank is empty, the sensor enables the dip tube and it is filled again. 

Then the water is made hot and supplied to the shower or tap. Because of the sensor, there is no option for the heater to blow its electric system or cause a fire. 

Danger 2:

On the other hand,  the tankless electric water heater turns on when we turn on the tap for hot water. Here it also comes with sensor operation. Here you need water in the pipeline, the water gets hot from the heater. 

Here if the water supply line is out of water, then it can be a disaster. The supply pipe can be harmed by too much heat and can melt if the heater is on for a longer time. We should be careful about this issue. 

Danger 3:

When we are using a gas water heater, it keeps the tank hot and delivers water to the tap. It starts heating when we start the system. If the tank is out of the water, it can cause problems. The tank can take high temperatures and sustain for a longer time, but the heating system may blow off. Recently updated systems have sensors, that will keep the system under control and make it safer. 

Preventive Suggestion

In the above circumstances, we should be careful while using sensorless systems. They do not understand whether the tank or water line is full of water or not. Being cautious will be the best preventive method here. If the tank and water line are out of water, just turn off the heater instantly

Tips to Stay Safe with Water Heaters

What happens if you turn on an empty water heater? It is a burning issue.  There are several cases of accidents with water heaters. The water pipes get melted, the heating system blows off and other issues are common in these accidents. So, we share some tips with you that can keep you safe. 

  • Always check the water level in tanks. If they are empty, avoid turning the heater on. 
  • Does the water tap have a water supply? This is important, or you cannot get instant hot water too. Just open the tap for 2-3 seconds and then you will understand it is out of the water, so turn it off. 
  • If the heater is on, and you are not getting any water in the tap? Turn off the heater immediately. It will keep you safe from any disaster.
  • Never keep the heater turned on when you have no water supply. It can cause serious electrical hazards with it. 
  • Just turn off the electric water heater if the water is unavailable.

If we are careful while using water heaters, we can avoid any kind of unexpected accident. 

Choose the Right Type of Heater

Choosing the right type of water heater can keep us safe from any possible incident. Now, most electric water heaters come with sensors. So, you cannot turn them on when it has no water. It means it is completely safe when you choose the right type of water heater and know the process to operate it. You can see the video to choose the right heater for you.

We have shared the technical specification and how the heaters work above. Hope those will help you a lot to use your water heater perfectly. Now we will discuss some common FAQs here for more information. 


How long can a water heater go without water?

It should not be more than 2-3 minutes. Turning off the water heater is the right method to apply. Otherwise, you can turn it off from the Breaker box too. Then it will be inactive. 

Can a water heater explode?

Yes, it is horrible. It may explode due to its poor make and gas issues. If the system is used frequently times and does not get regular servicing then it can be a bomb in the house. 

Should I turn my water heater off at night?

Generally, water heaters are not turned off for years. They run 24/7, but to make their life longer, we can turn them off at night. So, we can customize our use of the heater on our own. 

What are the signs your water heater is going out?

There are some symptoms. It will have rust deposits, metallic odor, and leaking murky water. All these symptoms will say that the heater is getting old and unsafe. We should not take any chances on them. 

Should I turn off the water heater if the water is off?

It will be the best preventive measure we can take. As soon as we turn it off, there is less risk. 

How many years does a water heater last?

Generally, water heaters last from 6 to 12 years. So, after 10 years, we should plan to change the heating system. It will give us a risk-free operation. 

Final Words

We have discussed in detail running water heaters without water based on real scenarios. Hope the provided information will keep you safe and now you know what to do. It will be a great thing if you get benefitted from this article and stay safe. 

About William

William is the founder of Fireplacehubs.com. He has real life practical skills in fixing smoker & heating appliance issues. He loves to share his knowledge & helps others in fixing their appliances & saving their money. William firmly believes that anyone can repair his or her unit with the correct guidance & knowledge. See more at about us.

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