Light switch question

[dandee]

Can I wire a immersion heater switch to be a normal light switch which shows the garage light is on by the LED on the immersion heater switch
Garage light switch is in the kitchen

 

[Avo Mk8]

That's a two-way light switch (there must be another switch also controlling that same light)
An immersion switch will be double pole but not two way.

 

[littlespark]

you will need a neutral wire at the switch position to power the LED on the switch.

 

[brianmoooore]

You can make up a grid switch with a 2way switch and an indicator light, connecting the indicator across the grey and black wires.
However, the light will indicate when the garage light is off rather than on, and there's a possibility of 'strange' effect if the garage light is LED.