Water heaters rarely explode, but they can, and it can be devastating when that happens. Failures or explosions may occur because of faulty installation or servicing by unlicensed plumbers. The following tips can help you avoid water heater explosions: Hire only a licensed professional to work on your water heater. Ensure your water heater’s pressure relief valve functions and replace it if faulty. Avoid setting your water heater's temperature above 120-125 degrees as higher temperatures increase internal heat and pressure. Be sure to have your unit serviced and cleaned out once every year.