Quick notes on Water Heater Timers:
1) The number one problem with the Timers called the Little Gray Box or LGB, is that after a power outage, the time will be wrong. So reset the time to correct time, and then review it later that day to make sure it is spinning
2) After a HECO power outage, sometimes the Timers just get jolted by the power spike on power return, and are fried.
3) They are electro-mechanical devices which work 24/7 and control a lot of amperage to heat your water. They will occasionally just fail and replacement is the answer, repair is too risky on this high power device.
4) If the timer tabs are put on too loosely, i.e. just by using hands, they can slide and jam, and this will occasionally cause the death of an LGB. Always use a tool to tighten down the on/off timer tabs.
5) In general timer tabs are set at 5AM on, 9AM off and 5PM on 9PM off. However, you can adjust these as you see fit. Those will smaller family sizes may choose to completely remove the “on” pins, thus preventing the heater from ever coming on by itself ---maximize savings, then you can still flip the switch to on when you know there is not going to be enough hot water. But keep the off pins in place, otherwise, if you forget to manually turn it off, you could get a high electric bill
6) When setting timer pins, it is safest to turn off the power at the breaker box, as there is live 240V inside the timer box.