Setting the Clock and Timer

It is good practice to switch your water heater on and off before and after use. However, unless we have cultivated very good habits, this is easier said than done. The built-in timer function available in most AOS digital heaters in comes in handy here. It allows you to set up to two timers for the peak shower periods in your household, usually in the morning and evening.

Set the clock timing for the digital panel before you set the timers.


When the clock timing is set, you may proceed to set your first timer. Usual peak shower periods vary but are commonly set for one-hour intervals.

Timer setting range:

Timer 1: 21:00(pm) to 08:00(am)
Timer 2: free range

If you would like to set your timer out of this range, please contact us and we will be glad to advise you.


At any time, press the ‘program’ key to toggle between turning on only ‘timer 1’, only ‘timer 2’, both timers or to turn off all timers.

Other water heater models

The control panel used for this tutorial is for the horizontal digital water heaters, model: CEWHR-PE6. For other water heater variations, the concept remains the same. Clock settings and the timer are adjusted with the ‘program’ button. See below for more detailed control panel diagrams.

For central heat pumps (HPI, HPA)


For micro heat pumps (HPW)


What happens during the non-timer period?

During the non-timer period and when your heater is set to ‘standard’ mode, the heater goes into ‘energy saving mode’. This means the heating elements are not activated during this period. Any balance hot water in your tank is kept hot for you like in a thermos flask. You can tell how much hot water you have left by referring to the 5 bar temperature indication on your control panel.

More: How is the timer affected on ‘standard’, ‘single’ and ‘multiple’ mode?

What if I need hot water during the non-timer period?

If your 5 bar temperature indication shows green bars and you have no hot water during the non-timer period, you may press the ‘instant’ button for water to be heated in your tank. The ‘instant’ button is an override button. It will work even during the non-timer period to give you enough hot water for one shower.

If I wake up at 6:00am for a shower, should I set my timer to 5:30am?

If you plan to have your first shower at 6:00am, you may set your timer to 6:00am.
Setting the timer from 6:00am to 7:00am means that the water heater will prepare hot water for you from the period 6:00am to 7:00am, so you can have a shower anytime within that range.

Enjoy using your timer but remember, you will save the most energy if you can switch your heater off after use!

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Amanda Zhong

Amanda is the bookish personality of AOS Bath. She loves reading in quiet places over a good cup of tea. Like her other Gen Y peers, she has a penchant for advanced technology that delights and engages people.

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