Water Heater Explosion Warning Signs (Video)

Last Updated On October 19, 2021
water heater explosion

Do you ever worry about your water heater exploding? Ease your fears by learning the water heater explosion warning signs and what you can do to prevent an explosion from happening. 

Water heater explosions happen when too much pressure builds up inside of the water heater tank. Tankless water heaters do not typically explode since they don’t have a storage tank, so this applies to conventional gas water heaters, conventional electric water heaters, and heat pump water heaters that use tanks. 

In this PlumbingNav guide, we will cover:

  • What you need to know about water heater explosions
  • Water heater explosion warning signs
  • What does a water heater explosion look like? (video)
  • How to avoid a hot water heater explosion
  • What should you do if your water heater explodes?

What's In This Guide?

      Water Heater Explosions

      Water heater explosions create serious damage. In fact, you can find numerous news stories about deaths caused by water heater explosions. The immense tragedy of a water heater explosion makes it important for every homeowner to understand what causes water heater explosions and how to prevent them. 

      What Causes Water Heater Explosions? 

      Water heaters create pressure when in use. Water heaters generate more pressure when the temperature gets too hot, or the water pressure gets too high. If the pressure builds up to extreme levels, the water heater will relieve pressure by releasing it from the pressure relief valve. If the pressure relief valve breaks, it won’t release the pressure automatically, possibly leading to an explosion. 

      An explosion can also occur if the pilot light comes into contact with gas from a gas leak or flammable liquid. This makes gas water heaters slightly more at risk than electric water heaters, but electric water heaters can explode, too. Many gas water heaters rest on water heater stands 18” above the ground to minimize the possibility of explosion.

      did you know can a water heater explode

      Water Heater Explosion Warning Signs

      Some of the signs that your water heater may soon explode include:

      • Popping noises
      • Leaking at the pressure valve
      • Sulfur Smell

      Popping/Whistling Noises 

      When sediment builds up in the bottom of your water heater tank, it will shake up while the device runs, causing popping sounds when the sediment moves around. As sediment develops, it can damage the thermostat and make it work harder or damage the pressure relief valve. 

      Whistling noises cause an even greater cause for alarm. The whistling comes from excessive usage of the pressure relief valve, indicating it regularly needs to open up and release excess pressure. 

      Leaking at the Pressure Relief Valve

      Pressure can cause the valve to experience too much strain and start to leak. Leaks can also develop over time due to natural wear and tear.

      If the pressure relief valve must constantly open and close, you may notice apparent leaks around the valve. Water will escape when the valve opens, causing the appearance of a leak. Check for a leak at the connection before assuming the valve needs a replacement. 

      Sulfur Smell

      Gas, while naturally odorless, contains a substance that produces a rotten egg or sulfur-like smell that will hit your nose when there’s a gas leak as a safety precaution. This can get extremely dangerous as the water heater will explode if the gas comes into contact with the pilot flame of many gas water heaters. 

      What Does A Water Heater Explosion Look Like? (Video)

      Watch these videos to learn just how devastating water heater explosions can get and why you need to take extra care to ensure that it doesn’t happen in your home. 

      News Coverage of Exploding Electric Water Heater 

      See the catastrophic effects of a water heater exploding inside the home in this story about an electric water heater that experiences too much pressure buildup from overheating and torpedoes out of the house like a rocket, landing 300 feet away. 

      MythBusters Exploding Water Heater

      Adam and Jamie from the award-winning show Mythbusters decide to test out the myth of exploding water heaters for themselves to give us another example of how intense the explosion can get.

      How To Avoid A Hot Water Heater Explosion

      All homeowners have a responsibility to take reasonable precautions to prevent hot water heater explosions. These tips can help prevent your water heater from building up enough pressure to explode. 

      Verify Safe Temperature

      Verify that your hot water heater produces hot water at an appropriate temperature. In most cases, you want to keep your residential water heater at 120°F and not any higher. Test your water heater thermostat to check your water heater temperature.

      If the water heater produces water higher than the temperature setting on the water heater, you will need to troubleshoot the problem to resolve the issue before it creates too much pressure buildup in the tank.

      Install a Water Softener 

      Hard water creates additional sediment buildup in your water heater tank since it contains more minerals. Install a water softener at your main water line to reduce the amount of sediment buildup affecting your water heater’s thermostat and allowing it to get so hot that it creates excessive pressure levels. 

      Flush Water Heater Regularly

      You can’t avoid all mineral deposits in your water heater. For this reason, you should flush your water heater regularly to get rid of any sediment in your tank. 

      In order to flush your water heater, you will follow the following simple instructions: 

      Step One: Turn Off Power to Water Heater

      As a precaution, turn off the power to the water heater at the circuit box. 

      Step Two: Close Cold Water Valve

      Close the cold water valve at the top of the water heater tank to prevent new water from entering the water heater. 

      Step Three: Open Drain Valve

      Open the drain valve at the bottom of the water heater to empty the contents of the water heater tank. Continue to empty the tank until you no longer see calcium deposits in the water. 

      Step Four: Close Drain Valve

      Close the drain valve to prevent water from escaping the tank. 

      Step Five: Open Cold Water Valve

      Now, you can reopen the cold water valve and fill the water heater tank with water again. Ensure that no water escapes from the drain valve. 

      Step Six: Verify Hot Water

      Once full, restore power to the water heater and ensure that you have hot water again in roughly 2 – 3 hours

      Replace Water Heater Drain Valve

      Most water heaters come with plastic drain valves that don’t last the entire life of the water heater. When you notice the drain valve starting to leak at the connection, you need to replace the drain valve. 

      When replacing your drain valve, consider upgrading to a metal drain valve that lasts longer. 

      Replace Water Heater After 10 – 15 Years

      Your tank-style water heater requires replacement every 10 – 15 years. If you use it too far past its expected life expectancy, the more dangerous the appliance becomes. Replace your water heater as necessary to prevent problems that can damage your entire house and even cause someone to get injured. 

      Use Water Heaters Without Pilot Lights

      Many homeowners prefer gas water heaters over electric water heaters and don’t want to make the investment to upgrade to a tankless water heater system. However, many gas water heaters still use a pilot light to activate the gas burner. This open flame can become dangerous if it comes into contact with gas or any flammable liquid. 

      Luckily, many gas water heaters now use an electric ignition that doesn’t require a pilot light, eliminating the risk. 

      What Should You Do If Your Water Heater Explodes?

      If your water heater explodes, it will create an immense amount of damage. Follow these simple steps after you experience a water heater explosion in your home. 

      Step One: Check on Family Members

      First and foremost, check to make sure no one in your home requires medical attention as a result of the explosion. If someone does require medical attention, call for an ambulance right away. You also need to call the necessary authorities in the case of fire and other dangers as a result of the explosion.

      If everyone appears safe, get everyone away from the home. 

      Step Two: Turn Off Power, Gas, and Water to Home

      You need to turn off water, gas, and power to your home to prevent additional danger or damage.

      Step Three: Breathe and Assess the Situation

      Once you realize that everyone in the household escaped danger, you can take a breath and cautiously assess the damage to your home. 

      Step Four: Call Your Insurance Company

      Call your insurance company as soon as possible. Luckily, most insurance companies allow you to file a claim at any time of day, so you shouldn’t have to wait until morning. 

      Step FIve: Restore Power, Gas, and Water

      Restore power, gas, and water to your home once safe. 

      Step Six: Buy New Water Heater

      Once you talk to your insurance company, you need to start shopping for a new water heater. To avoid an explosion from happening again, look into upgrading to a tankless water heater that doesn’t lead to explosion. 

      FAQ For Hot Water Heater Explosions

      What happens when a water heater explodes?

      Water heaters explode using incredible force that can send the water heater through the roof or walls of your home and shockingly high into the air. 

      What causes a hot water heater to burst?

      Pressure buildup and gas leaks cause water heater explosions. 

      Can a water heater kill you?

      Possibly. An explosion creates a lot of damage, and it can lead to severe burns and trauma that can sometimes become deadly. 

      Is a popping water heater dangerous?

      Possibly. Popping noises indicate sediment buildup, which can lead to excessive temperatures and excessive pressure. 

      Can an electric water heater explode?

      Yes. Both gas and electric water heaters can explode.

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      I'm passionate about all things plumbing, and love sharing tips, "how-to", and reviewing the latest products to help make your project a success!

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