WHAT YOU SHOULD KNOW TO HELP PREVENT YOUR HOT WATER HEATER OR BOILER FROM EXPLODING

Photo of a hot water heater

Some causes of catastrophic hot water heater and heating boiler failures (meaning violent explosions) are:

1. Improper adjustment of temperature controls or setting the temperature too high.
2. Altered or missing safety / relief valves which are called PT valves.
3. Work performed by unqualified or untrained personnel.
4. Lack of routine inspection and proper maintenance.
5. Lack of proper controls and safety devices.

Here is an example of the damage caused by a single hot water tank that exploded:

Photo of a demolished deck and wall


It is recommended that building and home owners either test or have tested the PT valves on all water heating appliances such as furnaces, hot water heaters and the like at least once a year. Please do not attempt to test a PT valve yourself unless you know what you are doing.

The PT valves on furnaces and boilers are usually checked by the people who clean and adjust them each year. Domestic hot water heaters are usually installed by plumbers who know how to check PT valves if you are unsure of how to do it yourself.

It is also recommended that you check or have checked the water temperature of your hot water heater. It should not be set to more than 180F. This is because most water heater thermostats cycle above their set point and 180F is as close to the boiling point of water (212F) as you ever want to get with any water heater.

Photo of a PT Valve

Here is a typical PT valve. It can be mounted on the top or side of your water heater. Can you find the PT valve in the photo at the top of this web page? Hint: look for the green circle near the center of the photo. Please, at least once a year have it checked or make sure it is working to avoid a catastrophe.