It’s not recommended to turn off the water heater at night, because when it’s off, the water temperature in the tank slowly drops. As a result, it will have to use more energy in the morning – for a shorter period of time – to heat up to a safe temperature for use. Turning off the water heater at night is therefore not advantageous, since the energy required to heat the water when the appliance is reactivated cancels out the minimal savings that could have been achieved. There’s no monetary advantage to turning off the water heater at night.

In addition, it’s not recommended to turn off the water heater at night, or to run it on a timed schedule, to protect it from potential bacterial growth. 

Ultimately, the best way to generate savings with Calypso is to use it with the Éco Sinopé feature, which works in conjunction with Hydro-Québec’s dynamic pricing to control energy demand during peak periods.