Hi rebelchai
Here in my State, we have tariffs on our hot water from supplier, they are the one that turn off & on the hot water via load control switch, a special meter in your meter box. One tariff cost 8.107 cent per unit and runs for 18 hours per day not at peak hours. (This is the one I am on). The other tariff cost 5.511 cent per unit and only run between 10pm and 7 am. If you don’t use a lot of hot water this one is Ok! I do turn down the temperature on my hot water and only run it on high if our winter is a cold one. I live in the sub-tropics in Australia. It’s time that I review my own tariff use here.
As for your question “How many KWH turning the hot water heater off will save me, and how long I should wait before taking a shower after I turn it on?” I wouldn’t be able to tell you. Your hot water system tank is larger than the one I have 140L (35 gallons). I do save money by not running my hot water system at its highest temperature.
I hope this helps you, I am sorry that I can’t answer you question.
