Both the 18L and 40L Sparge Water Heaters have a safety cut-off.

The thermal cut-off switch prevents a dry boil. This will happen if there is too low a level of water and if the element overheats - the thermostat will automatically cut off the heating element.

If you experience overheating, please wait a few minutes for the appliance to cool down and reset the temperature. 

For the boiler with the manual reset switch:

A manual reset switch is located at the bottom, underneath the unit. To reset the safety cut-off switch, turn off and unplug the unit, empty out any liquid, wait until the base temperature drops and then press the reset button/cut-off switch.

For the boiler with an automatic reset switch:

The new version of the Sparge Water Heater has an auto-reset button/cut-off switch at the bottom. If the reset switch tripped due to high temperature, switch off the unit, and wait until the base temperature drops, the auto-reset switch will reset itself.