I remember this Shopee Store Onsenmy has CENTON instant water heater models with power rating in the 5.xkW range and even 7.xkW range too, u can check with them. But do remember higher power rating means u need to use higher specs MCB / RCD, switches, and cables. U can refer to the Suruhanjaya Tenaga's guideline below for the correct electrical components specs to use.


If u don't want the hassle of upgrading your house's electrical components to cater for the higher power rating instant water heater, then just get a storage water heater like this. Storage water heaters are usually in the 3.xkW range or below, so u can use electrical components with standard specs for water heaters, but u might need modification to your piping setup (adding mixer, hot, and cold water pipings).

On the plus side, storage water heaters are definitely way sufficient for rainshower and even bathtub usage, and it is also hidden above the bathroom ceiling, similar like those found in hotels.

If u have a bathtub, definitely need to use storage water heater, as instant water heater won't be hot enough.

If u are using rainshower, warm water travelling up from the instant water heater to the rainshower head will pass thru the rainshower metal pipings, which cause quite a bit of heat loss. So better to get instant water heaters with higher power ratings (higher power rating generates hotter output water), eg. above 4kW range like CENTON models. I'm using CENTON Serene 4.2kW with rainshower, output water temperature is satisfactory, but do not expect storage water heater kind of hot water temperature.