Reasons Why Water Heaters Explode

Kenneth Wilson

Imagine a life without water heaters. You hop into the shower in winter but have to come out shivering! You can’t even do the dishes or wash clothes. You need a water heater for almost everything. Now, we’ve all heard stories of water heaters exploding and destroying property. Sometimes taking lives as well. And that might make you wonder; can a water heater explode? 

If you don’t care for your water heater correctly, it can explode. Putting excess pressure on the heating system can make the device flash. It could be from sediment build-up or because of a lousy anode rod too. 

So, you need to know the signs and how to prevent such an accident from happening. Let’s dive right into some details!

How Common Is It for A Hot Water Heater to Explode?

While water heater explosions aren’t common, they’re less rare than you may think. According to the National Fire Police (NFPA), in 2010, there were 5800 reported cases of water heater explosions. The estimated value of property damages was 104 million dollars. 

In 2016, a man in Stockton died while running maintenance on his water heater. The water heater exploded and left him with 3rd degree burns. Even though he was rushed to the hospital, he did not survive. It’s stories like these that has slowly created a public fear of water heater explosions. 

However, that doesn’t mean you should be afraid of your water heater. Instead, you should think of it as a good friend that you should take care of. And in return, it’ll give you years of quality service. 

What Causes A Hot Water Heater to Burst?

To defend against any unfortunate incidence, first, you’ll need to know what causes it. After all, knowing is half the battle. So, to defeat your enemies, you need to know about them. In other words, to stop a water heater explosion, you first need to understand what causes them. 

The primary reason behind most water heater explosions is excess pressure build-up on your water heater’s pressure system. Now, this incident can happen for a multitude of reasons. Let’s take a look at the most common ones. 

Corroded Tank

Steel build is a common trait of water heaters. And you know what is in steel? Iron. As your water heater gains more years, the water should cause the tank to rust. 

Thankfully, the engineers have also thought of that. So, they came up with a unique solution. They install a sacrificial anode rod for the tank’s protection.  

But you may ask: why are we calling the anode rod a sacrificial element? That’s because the anode rod is placed to rust instead of the tank. 

So, once the rod has run out of its use or gone bad, your water heart’s tank will begin to rust. And as the rust builds up, so will the pressure, leading to an explosion. 

Sediment Build-up

As you use your heater, sediment will settle in the bottom portion of your tank. The sediment is a combination of natural minerals that come from hard water and can insulate the water. 

Now, as the sediment layer builds up, your water heater’s heating ability will deteriorate. So, it’ll take longer to heat the water. 

If this runs on for too long, the heater’s tank will overheat, causing the heater’s pressure to rise over the safety levels. Finally, it’ll explode.

Excessive Internal Pressure

It’s basic science that if there’s more pressure in a container than its capacity, it’ll explode. 

Take balloons, for example. If you blow too much air in a balloon, it’ll pop. The same goes for water heaters. If too much pressure builds up in the heater’s tank, it can lead to an explosion. 

With that in mind, the manufacturers have set up a T&P relief valve not to let too much pressure build up. But as your heater gets older, its efficiency goes down, wearing down the tank. In extreme cases, your water heater can explode. 

Signs That Your Water Heater Might Explode

To ensure your water heater doesn’t explode, you need to know when things are going bad. Thankfully, there are a few common telltale signs that your water heater might be under too much pressure. 

Brown Water

If your hot water line is brown, get professional help. Brown water means that your heater’s tank is rusted and needs to be taken care of as quickly as possible. 

Popping Sounds

If you hear popping sounds coming from your water heater, that’s a clear sign that it needs some maintenance work done. This problem can arise if the sediment level has risen too much and needs to be addressed. 

T&P Valve’s Frequent Opening

The T&P valve is there to relieve the internal pressure inside the heater’s tank. Unfortunately, as it gets older, its efficiency decreases. 

So, to get rid of the excessive pressure, the valve keeps opening up more than it should. If you find that the valve’s opening more than usual, get it looked at. 

Rotten Egg Smell

Do you know what sulfur smells like? Rotten eggs. You can find sulfur in many things, especially in gas. 

So, if you ever come across this smell in your home, turn off your water heating unit. That’s because your heater’s pilot flame can come into contact with the gas and explode, putting you and your family in harm’s way. 

How to Prevent Water Heater from Exploding?

As long as you watch out for the warning signs, you can easily eliminate any possibilities of your water heater exploding. 

For starters, if you ever think that your water heater is not doing so fresh, cut off its power line. The heater should come with an instruction manual. Open it up and find out how to turn off your heating unit completely. 

Get professional assistance once you’ve turned it off if you’re not experienced dealing with such issues. But if you want to tackle these problems by yourself, here are some pointers.

Brown Water Solution

If you find rusty, brown water whenever you turn on the hot tap, it means that the anode rod has gone bad, and your heater’s tank is full of rust. Take a look at the anode rod and replace it with a newer one. 

To prevent this incident from occurring, get the anode rod looked at every two years. You can do it yourself if you want to. And if your heater’s warranty has run out, make it once every year. 

Popping Sounds Solution

If you hear popping noises coming from your water heater, it’s a sign that the sediment level has risen to a dangerously high level, and you need to get it inspected. 

As the sediment traps water under it, it keeps bubbling up as it tries to escape the mineral layer. As a result, you can hear some popping noises. 

To prevent this incident from ever happening, flush and drain the tank annually. But unfortunately, since you can’t stop the sediment from building up, you have to clean it out every year. 

T&P Valve Solution

If your T&P valve keeps releasing the pressure too frequently, it’s time to get it checked. To prevent it from wearing out too soon, avoid setting the temperature too high. Instead, keep the temperature around 120° to 125°. The higher the temperature you set, the more pressure will build up quicker.

Also, make sure to check the T&P valve’s condition twice every year. You can do it yourself with ease. 


The water heater is a much-appreciated invention. But it can be dangerous if not taken care of. So, look out for the warning signs mentioned above. I hope by now you have a proper idea of why and how can a water heater explode and the necessary step you should take to prevent that. 

Thanks for reading till the end & have a nice day. 

Kenneth Wilson
September 8, 2021

Kenneth Wilson

Retired contractor. Currently residing in Southwest Florida. Now in semi-retirement, I write and manage this blog focused on helping home owners make savvy decisions when it comes to finding contractors and getting their projects done. I also operate remodeling design service for homeowners.

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