Which type of valve would be inappropriate to use for anti-scald devices?

The water heater thermostat is not suitable for use in anti-scald devices due to its primary function, which is to regulate the temperature of the water within the water heater. Its operation is focused on maintaining a specific temperature, and it does not actively serve to mix hot and cold water during the delivery process to prevent scalding.

In contrast, pressure balance valves and mixing valves are specifically designed to help maintain a consistent water temperature despite changes in pressure from the hot or cold water supply. This allows for a safer experience by reducing the risk of sudden temperature changes that could result in scalding. Flow control valves play a role in managing water flow rates but are not directly designed for temperature regulation in the same way as the pressure balance and mixing valves.

Using the water heater thermostat for anti-scald applications wouldn’t address the immediate concern of temperature fluctuations that can occur while water is being dispensed, which is the primary risk that anti-scald devices aim to mitigate.