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Is electric storage water heater can really explode?

In view of recent news - The rupture of a storage water heater in a Cote D'Azur apartment in Marine Parade on Saturday (Sept 30) smashed the glass doors and windows of the unit's balcony. We hope our little effort of writing up this sharing can help contributing to our beloved community to increase awareness of electric water heater safety.

Is electric storage water heater can really explode?

water heater explosion

What an astonishment to know this is the least frequent question being asked by consumers even after this recent water heater explosion case. Is electric storage water heater can really explode? Nevertheless the answer is YES. The electric storage water heater could explode if it was not installed and maintained properly, and was still operated in unsafe conditions until all the safety devices failed. However a legitimate electrical storage water heater is generally very safe to use if it was installed and commissioned properly by qualified person. In addition a legitimate electrical storage water heater will come with safety devices to prevent water heater overheating which eventually will cause water heater explosion. Last but not least, please bear in mind the electrical storage water heater will not explode without electricity power turn on to heat water. Hence the safety level will increase tremendously if the water heater users are educated to notice faulty symptoms of a electric storage water heater.

In the following we will briefly explain on how an electric storage water heater works and then follow by discussion of important safety devices to be installed on an electric storage water heater. Lastly, we will highlight the faulty symptoms of a electric storage water heater which will lead to an explosion.

First of all let us take a look at basic operation an electric storage water heater. Basically, the electric

storage water heater is powered by electricity. When electric water heater is switched on, its heating element which controlled by thermostat will draw electric current and change electric energy into heat energy to heat up the water inside the water heater tank. Once water temperature reach desired level set by user then thermostat will cut off the electricity to heating element to stop heating. The thermostat will again cut in the electricity to heating element once water temperature inside water heater tank drops below satisfactory level. This process is repeating as long as there is electricity supply to electric water heater. Of course the actual operation details of an electric storage water heater are much more sophisticated than what we have just explained. If you would like to read more about water heater standard then you can find out more from IEC International Standards and water service Code of Practice of your local authority.

example of water heater connection diagram

At this point of time, we know you must be asking what will happen if thermostat failed to cut off ? The answer is heating element will continue to draw electricity and heat the water until overheating. At this state the temperature of the water inside the tank may rise above safe level. This time round, thermal cutoff safety device will come to save. A thermal cutoff is an electrical safety device that interrupts electric current when water is heated to a specific temperature above safe level. We need to avoid water inside closed tank to reach unsafe high temperature which will generate vapor or steam causing huge spike of pressure inside tank and rupture of tank. Seriously failure to stop overheating will cause tank explosion.

Explosion Hazard

This is why every electric storage water heater must be fitted with a matching and correct specification pressure release valve (It will be safer to have temperature release valve as well) as last resort to avoid explosion hazard when both thermostat and thermal cutoff failed. Water heater tank explosions are rare thanks to the widespread requirement for and use of pressure and temperature relief safety valves. But if the safety valve has been damaged, modified, or even omitted that condition, combined with overheating and over pressure can cause a water tank to explode. i

After all, there are faulty symptoms of a electric storage water heater to notice to avoid disastrous explosion hazard. Firstly, when you feel your hot water from water heater heater becomes too hot or hotter than usual, please stop powering on and using your water heater and then call a qualified technician to check your water heater. Secondly, if you notice your pressure relief valve is dripping or leaking more water than usual, have a qualified technician to check it. Always remembering do not plug valve, do not remove valve and do not tamper valve. Failure to follow these instructions can result in death or explosion. Thirdly, if you hear unusual noise or sound such as popping, hissing, crackling, banging, whistling, or other hot water heater noises from your water heater system, please also call a qualified technician to check your water heater.

Last but not least, base on average capacity of residential water heater in Singapore of 30 - 50 litres, we suggest users to only turn on water heater 15 mins before first use and turn off water heater 15 mins after last use. Practically we do not need thermostat repeating cut in and cutoff just to keep the water hot when we are away or water heater is not in use. Because a good quality water heater will have good insulation in between your heater exterior jacket and inner tank to prevent heat loss of unused hot water inside tank for 1 ~ 2 days. Do not forget electrical storage water heater will not explode without electricity power turn on to heat water. Of course if you are away for long period and water heater is in cold temperature, then precaution step is required to heat stagnated water to max temperature to kill bacteria and flush out old stagnated water before heating newly filled water for showering.

Please bear in mind there are many other installation mistakes mainly caused by inexperienced installer or ignorant general contractor that causing overheating or over pressure to the water heater system, in the end it turns out to be your family tragic incident. For example, thermal expansion is among the more serious of plumbing concerns, but one that many homeowners even installers and contractors know little about. Because many homes aren't at risk, it rarely seems to enter the typical plumbing discussion. Of the homes that are, many lack adequate protection, since code requirements are often lack of enforcement even on new installations. If you are not sure what is wrong with your water heater and don't know where to get help, then always please feel free to call our qualified technician to check your water heater at reasonable charge.

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