🔍 Key Concepts

• 46 CFR requirements for electric storage tank-type hot water heaters • The purpose of an independent temperature limiting device (safety cut-out) versus a normal thermostat • How high-temperature limits are set to prevent scalding and heater damage

💭 Think About

• Ask yourself: Is this device meant to operate every heating cycle like a thermostat, or only in an over-temperature emergency? • Look at the exact temperatures mentioned: which sound like a normal operating control, and which sound like a hard upper safety limit? • Consider what “independent” and “temperature limiting” imply about whether it should automatically reset or require manual intervention after an overheat event.

✅ Before You Answer

• Verify in 46 CFR what maximum water temperature is allowed for these heaters and whether there is any special mention of the upper 25% of the tank. • Check whether the regulation describes the device as manually reset or automatically reset after tripping. • Confirm whether the device must completely cut power to the heating elements or only affect a “secondary” or partial power supply.