Which safety device is typically used to prevent overheating in water heaters?

The temperature and pressure relief valve is essential for preventing overheating in water heaters. This safety device is designed to release water when the temperature or pressure exceeds predetermined levels, thereby preventing potential hazards such as tank rupture or explosion.

When water is heated, its temperature and pressure can increase significantly. If the system does not have a mechanism to relieve this pressure, it can lead to dangerous situations. The temperature and pressure relief valve acts as a safety mechanism, ensuring that excess heat or pressure is vented safely, thus protecting both the water heater and the surrounding environment.

When comparing this to the other options, the pressure relief valve is mainly focused on pressure regulation and does not directly address temperature concerns, which are equally important in preventing overheating. A thermal expansion tank is used for managing expansion due to heating, but it does not relieve pressure or temperature directly like the temperature and pressure relief valve. Lastly, a flow control valve manages the flow of water and does not have any safety features pertaining to overheating or pressure regulation.

Therefore, the inclusion of both temperature and pressure control in one device makes the temperature and pressure relief valve the appropriate choice for preventing overheating in water heaters.