Understanding the Causes Behind Electric Water Heater Explosions

Hello.
In practice, it happens (the daily press writes about it) that electric home boilers explode and (what is interesting) in such a room there is even damage to walls, windows, doors, etc.
I wonder how it happens that such serious boiler explosions occur and that the force of the explosion can not only kill or injure a person, but also cause the demolition of walls, etc., causing significant material losses in the room?

After overheating, there is high-pressure water vapor inside. This is why a pressure fuse is inserted in the water inlet to prevent the boiler from bursting. Regards

To prevent this, there must be a pressure valve and a functioning thermostat that will turn off the heater when the set temperature is reached.

Arson40 wrote:

Hello.
In practice, it happens (the daily press writes about it) that electric home boilers explode and (what is interesting) in such a room there is even damage to walls, windows, doors, etc.
I wonder how it happens that such serious boiler explosions occur and that the force of the explosion can not only kill or injure a person, but also cause the demolition of walls, etc., causing significant material losses in the room?

Hello, I have not yet seen such information in the press as you write, but maybe I don`t read enough. In my opinion, an increase in pressure that would burst the boiler can only occur as a result of negligence, i.e. first of all, a safety valve is always installed (it is added to the boiler when you buy a new one). The inlet valves would have to be closed, otherwise the pressure would expand in the pipeline, unless there is a non-return valve and, of course, a thermostat failure leading to the water in the boiler boiling. So many messed up issues in the boiler installation - this is only possible for a super careless person. Regards, Zbyszek

There is such a house near Częstochowa, which is currently uninhabited and no one renovated it after the explosion. The wall fell out. Such cases also happen. Firstly, there is a pressure valve in the supply, secondly, there is a functional thermostat, thirdly, behind the thermostat there is a bimetallic switch which is usually set to 80-90 degrees. I have access to a steam boiler every day and I once wondered why it had two safety valves with a diameter of 2.5 inches. Now I`m not surprised that the steam wouldn`t be able to escape because of the smaller valve. The boiler weighs 2-3 tons and contains about 700 liters of water. The same thing happens in a boiler with boiling water. The water boils and the steam increases in volume, so the pressure increases rapidly and the boiler bursts.

For no reason, the manual does not say to check the safety valve every two weeks. Currently, the safety valve is integrated with the non-return valve. Its design is such that in the event of a valve failure, water will flow back into the tubes, but the older version did not allow this. If a boiler breaks, it is more likely to burn someone than to physically damage the bathroom.

Have any of you encountered such a boiler explosion in practice? what then caused the explosion? What damage did the explosion cause in the room?

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janek1815 wrote:

..... Water boils and the steam increases in volume, so the pressure increases rapidly and the boiler bursts.

When the volume increases, the pressure does not increase

What`s probably worse is that water normally boils at 100*C, but it`s not normal there, because the pressure is getting higher and higher, so the boiling point is increasing... At least that`s what I think. I wonder how much *C it can reach right before the explosion?
Although for a person in such a room, it probably makes no difference...

Besides, imagine just tearing apart such a metal wall! Ouch!

It`s not as scary as you write. The boiler sheet is thin and insulated, which is again covered with a sheet metal casing. If the water installation is properly installed, nothing serious can happen. Gas in the house is a much greater threat.

Each electric boiler has three protections - a thermostat, a thermal switch - the so-called thermostat and pressure valve. If the thermostat fails, the thermal switch, i.e. thermistor, will activate. This switch works on a similar principle to the switch for a cordless kettle - it will turn off the heater when the water reaches a dangerous temperature - approx. 80 - 90 degrees. To start the boiler, it is necessary to manually turn on this switch, but in such situations I would always recommend checking what caused the thermostat to activate, because this is not a normal situation, and check the operation of the thermostat - you can turn on the boiler`s thermostat and turn the thermostat knob through the entire range. temperatures. An efficient thermostat should turn the boiler off and on in some intermediate position (a gentle "ticking" of the contacts can be heard, and the heater is switched on by an indicator light; moreover, when the heater is turned on, a drop in voltage in the network can be observed - turn on the light - you will notice the bulbs dimming). If the thermostat is damaged, the boiler will operate regardless of the set temperature, turning the thermostat knob will not turn off the heater - then the thermostat must be replaced. The third protection is a pressure valve - the so-called a safety valve that will allow excess water to return to the pipes in the event of a sudden increase in pressure. If possible, a good way to avoid a tragedy is to install the boiler in a room where you rarely and briefly stay, e.g. in the basement - this is how I have the boiler installed. Then, any explosion will only cause chaos in the room and it is unlikely that anything will happen to anyone.

http://m.regiodom.pl/portal/wiadomosci/inwest...po-Explozji-bojlera-kamienica-grozi-zawalniem

Are you saying it`s nothing? Thin sheet metal?