I've tried to replace my Clipsal heater switch (the one with rocker switch and a red indicator light). Upon fixing all the cables, i can see the light turned on brightly when i switch on the heater switch. However, when i switch off the heater switch, i can still see faint red light on (not as bright as when the switch is on).

Any idea why? Is the switch faulty? Or wrong wiring? I tried to disconnect the small cable that link to the indicator light and this indicator light is not turned on whether the switch is on or off.

Appreciate some help from electrical guru.

seems like got current leaking...

ori clipsal or china tiru mari ?

If the switch is working properly, the light should not lit when the switch is turn off.
Return it to the shop and get a replacement

or your water heater having current leaking?

How you connect the wire to the switch?
Incoming Live+Neutral should connect to LINE side terminal
Outgoing to the heater should connect to the LOAD side terminal

what is the rating for it ?
10 , 30mA ?

fix it as you mentioned. i got the sequence of the wiring wrongly since both live wires have same color, not sure which one is incoming and outgoing. so i swap the live connection and it works.