Hi,

I have a removed a 3kw electric shower and the cable is still installed with RCD. Could I T off this and power up immersion heater?

Also, can I power extractor fan from lighting circuit?

Thanks for your help.

As long as the voltages are the same and wattage is the same or less, you can use the heater but make sure it is GFCI protected. Bath fans are commonly connected to the light circuit and draw very limited amperage, you should be OK.

As long as the voltages are the same and wattage is the same or less, you can use the heater but make sure it is GFCI protected. Bath fans are commonly connected to the light circuit and draw very limited amperage, you should be OK.This is obviously not a US or Canada installation. I assume UK or Australia. An RCD is the equivalent of a GFI.

Due to the difference in codes and terminology I will refrain from commenting further.