Can water heaters explode? Yes, but it’s rare. The U.S. Consumer Product Safety Commission (CPSC) reported two cases of water heater explosions in 2022. This was out of 108 water heater incidents.
That being said, “rare” doesn’t mean “impossible.” In August 2024, a water heater exploded in a San Antonio apartment building, igniting a fire. It’s a stark reminder that these things do happen.
Water heater explosions, whether gas or electric, can have devastating effects. The main culprit? Neglected maintenance. That’s why it’s essential to recognize the signs that something’s wrong before it escalates into a catastrophe.
Key Takeaways
- Water heater tank explosions are rare but dangerous.
- Both gas and electric heaters are susceptible if maintenance is ignored.
- Temperature and Pressure (T&P) relief valves are key safety features, and malfunctioning valves are a major risk factor.
- Warning signs like leaks, noises, and unusual smells could indicate trouble.
- Regular maintenance and temperature monitoring reduce explosion risks.
Evolution of Water Heater Safety
In the early 1900s, water heater explosions were far more frequent, largely because safety mechanisms weren’t what they are today. In fact, many homeowners lived with a ticking time bomb in their basement. The introduction of the Temperature and Pressure Relief Valve by George Horne changed all that.
Before the T&P valve, pressure relief systems were unreliable. They often failed to discharge excess pressure, leaving water heaters primed for an explosion. The modern T&P valve, which is standard on all heaters today, is designed to release pressure when internal levels get too high. If it weren’t for this valve, explosions would still be a far more common threat.
The T&P valve isn’t something new. It’s been around for over a century, evolving in both design and reliability. Nowadays, they come in different models, all readily available at any hardware store, giving homeowners an extra layer of protection.
What Causes a Water Heater to Explode?
There’s no single reason why a water heater might explode. Several factors can lead to a catastrophic failure, from simple malfunctions to outright neglect. Below are the primary reasons why water heaters pose a risk.
High Internal Temperatures and Pressure
Water heaters regulate internal temperature and pressure using safety mechanisms. When these mechanisms fail, pressure builds up inside the tank, leading to potential disaster. The combination of heat and pressure creates a volatile environment that, if not managed, can force the tank to rupture.
Overheating Due to High Temperature Settings
Cranking up the thermostat might give you hotter showers, but it also invites danger. High temperature settings cause thermal expansion, which increases internal pressure. Over time, this added strain wears on the safety systems, potentially leading to an explosion.
Sediment Buildup
As water heats, minerals like calcium settle at the bottom of the tank, forming sediment. This sediment creates a layer that insulates the heating element, causing the heater to work harder and get hotter. The higher temperatures lead to pressure increases that could cause the tank to fail if left unchecked.
Rust and Corrosion
Water heaters are mostly made of metal and metal rusts. When components inside the heater corrode, they lose strength. A weakened water heater is less capable of handling high pressure, making an explosion more likely.
T&P Relief Valve Malfunction
The T&P valve is the unsung hero of water heater safety. When pressure or temperature gets too high, the T&P valve opens to release steam or water. But if this valve malfunctions—whether it’s blocked, broken, or improperly installed—it won’t relieve pressure, and the tank could explode.
Gas Leaks
Gas water heaters present an additional risk: gas leaks. When gas lines are damaged or improperly installed, even the smallest leak can build up and lead to an explosion. The pilot light or any spark can ignite the gas, turning your water heater into a potential bomb.
Water Heater Explosion Warning Signs
You don’t need to be a plumber to catch the warning signs of an impending water heater explosion. Many of these indicators are easy to spot. But the moment you notice one, it’s time to call in a professional—stat.
Leaking T&P Valve
The T&P valve should remain closed unless it’s relieving excess pressure. If you notice a slow leak, that’s a clear sign the valve is struggling to keep up. Valve leaking means there’s too much pressure inside the tank, and that’s a recipe for disaster.
Constantly Open T&P Valve
A valve that’s stuck open is just as bad as one that won’t open at all. If the valve constantly releases steam or water, it means the heater can’t regulate its internal pressure. This constant release might prevent an explosion in the short term, but it also signals a serious underlying problem.
Rotten Egg Smell
One of the most recognizable signs of a gas leak is the smell of sulfur, often described as “rotten eggs.” If you smell it around your water heater, shut everything down and call for help immediately. The sulfur smell indicates a gas leak, and with a pilot light nearby, the risk of an explosion skyrockets.
Popping Noises
Hearing popping or banging sounds coming from your water heater? That’s sediment buildup. The trapped water under the sediment is trying to escape, and when it does, it creates a popping sound. If ignored, this buildup can cause overheating and pressure spikes.
Brown Water
If your water comes out rusty or brown, that’s a sign of corrosion inside your heater or its pipes. Not only is brown water unsafe to drink, but it also points to rusted internal components that could fail under pressure.
Poor Installation
Poorly installed water heaters are accidents waiting to happen. Whether it’s a gas line that isn’t sealed correctly or electrical wiring that’s not up to code, bad installation increases the likelihood of pressure buildup or leaks. If you’re not sure your heater was installed properly, have a professional take a look.
Shaking Water Heater
Is your water heater shaking like a washing machine on spin cycle? That’s a huge red flag. A shaking water heater indicates something is severely wrong, and you should shut it down immediately. A tank that’s moving is one step away from blowing up.
How to Prevent a Water Heater Explosion
Now that you know the risks, what can you do to prevent them? Regular maintenance is your best bet, but there are a few other steps you can take to keep your water heater safe.
Keep Water Temperature Below 120°F
Setting your water heater’s temperature below 120°F is one of the simplest ways to reduce pressure. Higher temperatures cause thermal expansion, and more expansion means more pressure. If your water heater is in a commercial setting where higher temperatures are necessary, make sure you use metal T&P valves designed to handle the heat.
Monitor Pressure Levels
Most modern water heaters have a control panel that shows the pressure. Make it a habit to check those numbers regularly. Know what your heater’s pressure rating is, and if the levels creep higher than normal, get it looked at.
Regular Maintenance
An annual maintenance routine will catch many issues before they become serious. Flushing the tank to remove sediment and inspecting all components for rust or damage should be a part of your yearly checklist. Regular check-ups not only keep your water heater running efficiently but also help prevent catastrophic failures.
Contact Apollo Plumbing for Water Heater Issues
When it comes to water heaters, the risks are too great to ignore. A water heater explosion can cause significant damage to your home and plumbing, not to mention the serious risk of injury or worse.
If you notice any of the warning signs mentioned above, call a plumber immediately. Apollo Plumbing has a team of experienced professionals who specialize in water heater repairs, maintenance, and replacements. We’re your “Ready Right Now” plumbers, always available to tackle emergencies.
Final Thoughts
Exploding water heaters are rare, but the risk is real. By monitoring for warning signs and scheduling regular maintenance, you can greatly reduce the chances of an explosion. Stay proactive, and if you’re in the Everett, WA, area, give Apollo Plumbing a call. We’ll make sure your water heater is running safely and efficiently.
FAQs
Water heater explosions are a concern for many homeowners. Below, we’ve compiled some frequently asked questions to help you better understand the risks and prevention methods.
Can a water heater really explode?
Yes, although it’s rare. Most modern water heaters come with safety features like the T&P valve to prevent explosions, but neglected maintenance or a malfunctioning valve can lead to an explosion.
What are the main causes of a water heater explosion?
Common causes include high internal temperatures and pressure, a faulty T&P valve, sediment buildup, and gas leaks.
How can I tell if my water heater is at risk of exploding?
Warning signs include a leaking or constantly open T&P valve, popping noises, rotten egg smells (indicating a gas leak), and brown water. If your water heater is shaking or installed poorly, call a professional immediately.
How often should I maintain my water heater?
Annual maintenance is recommended. This includes flushing the tank to remove sediment, checking the T&P valve, and inspecting for corrosion or rust.
What temperature should my water heater be set at?
For most households, a safe temperature is below 120°F. Anything higher can cause dangerous pressure buildup.
What should I do if I smell gas near my water heater?
If you detect a rotten egg smell, which indicates a gas leak, shut off the gas supply, ventilate the area, and contact a plumber immediately.
How long does a water heater last before it becomes a safety risk?
Water heaters generally last between 8-12 years. After that, parts begin to wear down, increasing the risk of failure.
