What would happen if your water heater suddenly exploded while someone was taking a shower?

As the cold season approaches and chilly winds sweep through northern Vietnam, hot water becomes a daily necessity. For households in the North, a water heater is almost an indispensable bathroom appliance—especially on frigid mornings when a burst of warm steam is the only way to make showering possible.

On November 14, social media erupted with news of a water heater explosion in Quảng Ninh. Fortunately, no one was hurt, but the incident caused significant damage to the homeowner’s bathroom and nearby belongings.

Why did it explode?

According to information shared by VTC News, the water heater blew up because the homeowner kept it running 24/7 and only turned it off right before taking a shower.
This is a critical and dangerous mistake—one that many people unknowingly repeat until a disaster happens.

No one wants to imagine a water heater exploding while they’re showering, but such accidents can happen if you continue to make the following three extremely dangerous mistakes.

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1. Keeping the water heater on almost all day

For families with small children or frequent hot-water needs, leaving the heater on continuously might seem convenient. But in reality, it exposes the device to heavy stress and increases the risk of serious malfunctions.

When a water heater operates nonstop, the insulation around the electrical wiring gradually deteriorates. Over time, this reduces the effectiveness of the circuit protection system. Once the insulation weakens, the heater becomes prone to short circuits or electrical leakage—both of which can trigger an explosion.

Many people underestimate this risk because their water heater has “worked fine for years.” But just like any electrical appliance, constant operation accelerates wear and tear, slowly turning the heater into a hidden time bomb.

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2. Not turning off the heater while showering

One of the most important safety rules is to always turn off the water heater before stepping into the shower. Failing to do so is a major cause of electrical shocks and fatal accidents in bathrooms.

Modern water heaters are equipped with automatic shut-off relays, which make some users overly confident, assuming the device eliminates all risks. But auto shut-off does not guarantee absolute safety. If the heater is old, poorly installed, or has internal parts that are worn out, electrical leakage into the water can still occur.

It only takes a single malfunction—just one moment of electrical failure—for a relaxing shower to turn into a life-threatening situation.

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3. Skipping maintenance and cleaning

Maintenance is something most people rarely think about, especially because many do not know how to service a water heater themselves. As a result, some devices go 8–10 years without ever being inspected—an extremely dangerous practice.

Inside every water heater is a heating rod. Over time, minerals and impurities in the water accumulate on this rod, forming thick layers of sediment. This buildup slows down heating efficiency, increases electricity consumption, and forces the heater to work harder than it should.

If the heating element becomes corroded or damaged, it can short-circuit, overheat, or even ignite—dramatically increasing the likelihood of an explosion.

For these reasons, experts recommend professional maintenance at least once a year, or every two years at the latest. Regular servicing can detect early signs of wear, prevent electrical risks, and extend the life of your heater.

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Final Reminder

Your water heater is one of the most frequently used electrical appliances in your home, yet it is also one of the most overlooked. A few seemingly harmless habits—leaving it on all day, showering without turning it off, or neglecting maintenance—can quickly become deadly.

Taking a few simple precautions could be the difference between safety and disaster.
Don’t wait until something goes wrong—fix your habits before it's too late.