Lot of people have a misconception that thermostat makes sure that water heater is switched off when the water is heated. People have a tendency of leaving the water heater “ON” all the time thinking that the thermostat will take care of switching it off when the water is hot. This tendency can lead to lot of electricity wastage. All water heaters loose heat through their body. Water once heated if kept stored in the heater will loose heat and the water temperature will come down. Once the temperature of the water is down by certain degrees, the thermostat switches on the water heater again. The heat loss happens all through the day and so if you do not switch off your water heater, it will keep working all through the day and will consume electricity. Even thermostat uses electricity for its operation (although very less), but keeping it on throughout the day will result in significant consumption of electricity.