Five-hole power socket is not suitable for high-power electric water heaters. The five-hole power outlets are all 10A, and the power of your electric water heater is greater than 10A, so it is easy to burn out the plug. If you want to use the three-hole power socket of 16A, you'd better buy the power socket of 16A switch, so you don't need to plug in and out the power plug often, just turn off the switch. Or directly unplug the power socket and install the 16A air switch with protective cover for use.