Can a Water Heater Explode? Yes, it Can. Find Out How to Prevent it Here!

Warning! Water heaters explosions are a reality.

Water heaters are an everyday necessity, providing the comforting warmth of hot water for showers, cleaning, and cooking. Yet, few of us pause to consider the potential dangers hiding within this seemingly harmless appliance.

In this discussion, we tackle a critical question: Can a water heater explode?

Uncover the surprising answers and gain valuable insights into the safety measures every homeowner should be aware of to protect their families and homes from this potentially catastrophic event.

Heating your domestic water eats up almost to 20% of your home energy costs annually, so your water heater must be looked after. It's an essential part of your family's life and well worth ensuring it's looked after regularly.

If your water heater bursts and floods your home, that is in the top 20% of water damage issues, according to a report from the Insurance Institute for Business and Home Safety (IBHS).

They report the average claim was just under $4500. But you can relax, can't you? Your water heating system is well maintained and serviced, right?

No? Then you should read on; it could save from serious injury or even kill you.

All it takes are a few simple things that will prevent you from becoming a statistic because flooding is potentially the least of your concerns.

All you need to do is visit your water heater occasionally.

I know it's a pain. It's like visiting relatives you can never find the inclination to visit with. You know you should, but we always find something better to do, don't we?

Try not to put it off.

Explosions can kill

Explosion sign - danger

See this label? It's fitted to water heaters, and it's a serious warning. It's not put there for amusement. Water heater explosions are a reality and not fun at all. The effects of an exploding water heater outdo simple flooding by a considerable margin, of the scale, in fact. 

Explosions can cause serious injury or even kill someone in your family, but they are always devastating. Think about this; is your insurance still going to cover something caused by lack of maintenance? Perhaps not. One thing's for sure; it will cost way more than the average $4500 claim if you need to build a new home.

OK, enough of the scary stuff. You've visited your out-of-sight-out-of-mind relative, sorry, your trusty water heater, so what do you do now?

Causes of water heater explosions

Exploring the causes of water heater explosions is crucial for homeowners, as it sheds light on potential hazards that can impact both the appliance's functionality and household safety.

  • Overheating
  • Excessive pressure
  • Corrosion and rust
  • Neglected maintenance


Overheating is a common cause of why water heater explodes and can occur due to several factors.

High temperature settings on your water heater can put excessive stress on the tank and its components. When the water temperature becomes too high, it can lead to weakened structural integrity, increasing the risk of an explosion.

Additionally, sediment buildup at the bottom of the tank acts as insulation, making it harder for the heating element to transfer heat efficiently, which can result in overheating.

Excessive pressure

Excessive pressure within a water heater can also lead to dangerous situations.

Pressure relief valves are designed to prevent this, but if they fail to operate correctly, or if your system lacks proper venting (Closed system issues), pressure can build up rapidly.

The tank is not designed to withstand high levels of pressure, and if it exceeds its limits, it can rupture, causing an explosion.

Corrosion and rust

Corrosion and rust are natural processes that affect metal over time. In the context of water heaters, when the tank or its components corrode, weakened areas can develop.

These weak spots become vulnerable to leaks and, in extreme cases, may lead to structural failure.

Corrosion compromises the integrity of the tank, increasing the risk of explosions.

Neglected maintenance

Neglected maintenance is a contributing factor to all of the above causes. Without regular maintenance, issues like sediment buildup, corrosion, and pressure relief valve malfunction can go unnoticed and unaddressed.

Neglecting your water heater can lead to a cascade of problems that ultimately increase the chances of an explosion.

Regular inspections and maintenance are essential to prevent these issues and ensure the safe operation of your water heater.

How to prevent your water heater from exploding

Gas tank-type water heaterGas tank-type water heater

Regular maintenance

Regular maintenance is the first line of defense against water heater explosions.

This includes tasks like flushing the tank to remove sediment buildup, which can lead to overheating, and replacing the anode rod to prevent corrosion. These simple steps can extend the life of your water heater and keep it operating safely.

Note that over time, natural residue from your water drops to your heater's tank base, creating a layer that separates the water from the power source, often a gas burner.

This will cause your burner to work harder and longer to bring your water up to temperature. As the layer thickens over time, it can cause the system to overheat and damage the tank and much more besides.

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Listen to the sounds your water heater makes

Listen to the sounds your water heater is making. It could be a sign that something is wrong. If you hear bursts of popping or bumping sounds, it's water trapped under the layer of residue expanding and escaping into the main tank.

While these sounds might be enticing if you're boiling a kettle on a camping stove in the great outdoors, within your water heater, they are signs that all is not well.

Prevent tank residue

The tank should be cleared of residue at least once a year, especially if you reside in a hard water area. Hard water contains minerals that can accumulate as sediment.

Some newer water heaters come equipped with a self-cleaning system, which reduces the need for frequent maintenance, possibly requiring cleaning only once every three years.

Corrosion risks and water heater explosions

Steel has been a popular choice for water heaters, but here's the catch: it tends to rust when it meets water. That's why, along with glass-lined tanks, stainless steel models are gaining popularity.

However, in areas with water supplies high in chlorine content, stainless steel is also susceptible to corrosion unless you use a very high-grade material. Stainless steel comes in various grades, with the most common ones used in water heaters being 304, 316L, 316Ti, and 444. The higher the grade, the more expensive it is, but it also offers greater longevity.

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Replacing an old water heater when necessary

Water heaters indeed have a limited lifespan, usually ranging between 10 to 15 years. As they age, the risk of potential issues, including the possibility of explosions, can increase.

Therefore, it's crucial to pay close attention to the condition of your water heater.

If your current unit is nearing the end of its operational life or displaying signs of wear and tear, it's advisable to contemplate replacing it with a newer and more efficient model.

Upgrading your water heater not only enhances safety but also offers several other benefits.

First and foremost, modern water heaters are designed with advanced safety features and materials, reducing the risk of overheating and pressure build-up, which are common precursors to explosions in older units.

Furthermore, newer models are often more energy-efficient, leading to reduced utility costs and a smaller environmental footprint.

By making this proactive investment in your home's safety and efficiency, you not only gain peace of mind but also contribute to a greener and more cost-effective household.

Check the water heater anode as recommended

The other component requiring attention is the anode, a lengthy rod situated inside the tank with the role of drawing rust away from the steel tank's inner wall.

Typically constructed from a magnesium alloy, it functions as an anode to the water tank's wall, which acts as the cathode. This rod is often referred to as a "sacrificial anode" because, as time passes, it undergoes corrosion instead of the water tank itself. This sacrificial process effectively extends the life of the water heater tank, but this is contingent on its condition being well-maintained.

In the case of stainless steel water heaters, they do not utilize an anode; however, they are still integrated into glass-lined tanks to safeguard against damage to the steel. It is advisable to inspect these anodes every two to three years.

Prevent explosions by checking the temperature and pressure relief valve

The last critical item is the temperature and pressure relief valve (TPR valve), which is there to protect you and your family from the extreme pressure inside the tank and a life-threatening explosion. It opens automatically should the pressure in your water tank exceeds the limit set by the manufacturer. The relief valve and your thermostat work in harmony to keep you safe.

If the valve fails to open when the pressure in your water-heater tank rises above the acceptable level, there is a danger of an explosion. Think of a balloon being over-inflated; it eventually ruptures and explodes. It's the same thing here if there's too much pressure, and it's unable to release, something has to give.

The reason the pressure relief valve may fail could be one of many. Manufactured equipment fails; it's a fact. It can be jammed open or closed by a build-up of minerals and other debris that flows into your heater in freshwater intake.

That simple blockage could cause flooding if it jams open. But if it jams closed, it could be deadly. It needs to be checked regularly to make sure it opens readily, allows water to flow then closes again tightly.

Preventing explosions is not rocket science

It's not rocket science, but if it blocks solid, it could cause your water heater to become a rocket.

Exploding water heaters tend not to go off like a bomb but much more like a propelled rocket, straight upwards and through your floors and roof. One example traveled over 439 Feet into the air before returning to earth, which is further than some recent large-scale rockets managed to achieve!

The number of exploding water heaters is relatively small, thankfully almost as small as the households who do basic maintenance on their water heater each year. You check your car is safe for your family by ensuring it's maintained and checked for apparent faults, so why not your water heater?

YouTube video: Mythbusters Water Heater Explosion

Which types of water heaters are  more liable to explode?

Storage tank water heaters 

These are the most common type of water heaters used in homes today. These units are perfectly safe, provided they are regularly maintained and checked. They should be professionally serviced once a year for safety.

Tank-type heaters are designed with a water storage tank that can store over 100 gallons of water, and as they are prone to high-pressure situations, they include a safety pressure relief valve.

Tankless water heaters

Tankless water heaters are usually smaller because they have no large storage tank attached and heat water on demand using gas or electricity. These units are generally very safe, but, as with tank-type models, there have been some past recalls by the CPSC (Consumer Product Safety Commission).

Point of use water heaters (POU)

POU (Point of Use) water heaters work in the same way as tankless units, heating water on demand as it passes the heating source, or like tank-type water heaters equipped with a storage tank. A typical installation would involve a single-point water heater at a sink, for example.

Larger, more powerful units are available for small homes or bathrooms with limited hot water needs. However, they do have the potential for an explosion if not appropriately maintained.

Heat pump water heaters

Heat pumps for heating water (hybrids) can be stand-alone units fitted on top of a 20 – 80-gallon storage tank. These typically have backup heating elements installed so that if the water temperature isn't high enough, you can boost the temperature.

Heat pump water heaters can also work in conjunction with a standard, existing storage water heater. The same cautions apply as the tank is fitted with a pressure relief valve for safety, and if it fails, there is a risk of explosion. Basic maintenance and an annual professional check by a registered plumber are essential.

Solar water heaters

Solar water heaters can only provide around 60% of the hot water used in an average house.

They work in tandem with a conventional water heater by pre-heating the water. It subsequently reduces the total amount of energy you use to heat your water as the water entering your water heater is much warmer than from the regular water supply. 

The conventional water heater they work with carries the same risk of explosion if not properly maintained and serviced annually by a professional plumber.


Heating your domestic water supply accounts for up to 20% of your annual home energy costs, making it a significant part of your household expenditure. It's crucial to ensure that it's well-maintained and operating efficiently, even though it often gets overlooked. Despite working tirelessly to provide us with hot water 24/7, water heaters tend to be neglected until they encounter a breakdown, at which point our perspective changes drastically.

One crucial fact to bear in mind is that water heaters can and do explode, a highly dramatic event that captures our immediate attention. However, you can avoid such catastrophic incidents by incorporating a few basic maintenance routines into your regular schedule.

Homeowners should take the initiative to educate themselves about the warning signs of potential water heater problems. Unusual noises, leaks, fluctuations in hot water temperature, rusty water, and high energy bills all serve as indicators that something might be amiss. Recognizing these signs early empowers you to take prompt action, effectively preventing potential explosions and costly damage to your home.

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