Correctly installed electric water heaters are safe. They alleviate safety concerns associated with natural gas heaters, such as combustion and carbon monoxide poisoning, and a study from the Consumer Product Safety Commission finds that there are significantly fewer fire-related injuries and deaths caused by electric water heaters.
The electric water heater's thermostat, pressure valve and insulation are three important components of the system that ensure safety. A broken thermostat improperly regulates water temperature, which can cause pressure to build inside the water heater. If pressure continues to build without relief, the water heater explodes. A working pressure and temperature valve releases water and pressure, ensuring this does not happen. Insulation also makes certain that the thermostat reads the temperature inside the water heater and not the temperature outside the water heater.