What is required on all electric water heaters for safety?

The requirement for a shut-off switch or disconnect on electric water heaters is essential for safety and maintenance purposes. This switch allows for quick and easy disconnection of power in the event of an emergency or when servicing the unit. It ensures that anyone working on the water heater can safely perform maintenance or repairs without the risk of electrical shock. By having a readily accessible shut-off switch, homeowners can also turn off the unit during prolonged periods of non-use, helping to prevent overheating and potential hazards associated with a malfunctioning device.

While other components like pressure relief valves, thermostats, and expansion tanks play significant roles in the operation and safety of water heaters, the shut-off switch is specifically critical for providing a quick, safe method to manage electrical power, making it a key safety feature for electric water heaters.