A plumbing myth can be created when bad or incomplete information is repeated often enough so that over time it becomes regarded as a wise rule of thumb for plumbing issues. Here are a few examples of common plumbing myths that we hear from time to time, and wanted to provide some insights to each.
Myth: It is Not Possible for A Water Heater To Explode
False: It is not common for a water heater to rupture or explode because of two main safety measures, however it is possible, and that is why proper water heater maintenance is important.
Your hot water heater is likely heated by a gas flame or an electric coil. The hot water heater has a thermostat that controls the temperature of the hot water in the water heater. When the stored water in your tank reaches a certain temperature the heat source is turned off by the thermostat. If the thermostat malfunctions and does not turn off the heat source (electric coil or gas flame) then the water can continue to heat up possibly to the boiling point. If this happens then the steam that is generated at boiling creates a high pressure in the tank that the water heater was not fully designed for, resulting in a burst or explosion. Obviously, that could be very dangerous.
So, as a safety feature to help prevent this likelihood of an explosion from happening, each water heater has a safety valve built into the top of the tank, it is called a “Temperature and Pressure Release Valve” (T&P valve). If the thermostat were to fail, the T&P valve is designed to automatically open up and release the steam pressure buildup (like a pressure cooker) so the pressure does not continue to build until the tank ruptures or explodes. The T&P valve normally will discharge to the outside, or into an adjacent sink drain.
The T&P valve is an important safety feature so it is a good idea to have the T&P valve tested annually to make sure it will operate properly if it is ever needed. For various reasons such as hard water build up, manufacturers defect, etc. the T&P valve may stick and not properly open up to release pressure if needed.
Our plumbers can easily test the T&P valve to make sure it is functioning properly. If it is found to be defective, then the T&P valve can be removed and replaced. It is a good idea to have an experienced plumber help with this test and replacement if you are not familiar with the process. As an important safety feature it is important that the T&P valve be operational if/when it is needed. If you would like assistance with this we would be happy to help, give us a call.
So, although it is possible for a water heater to burst or explode, it is necessary for both the thermostat and the T&P safety valve to fail. This is why such an event is not common, but it is also why proper maintenance of the water heater is needed to help ensure these safety features are operating properly.