UK Wiring up an immersion heater to a smart switch - what do I do with the earth wires?

[Feroze]

Having just replaced an immersion element with its life expired cable and switch, I'm thinking of replacing the switch (20A double pole) with a smart version so that I can control the hot water from my phone etc.

Both the immersion heater and the current switch have earth terminals, however the smart switch only has neutral and live connections.

If I do go ahead, what should I do with the earth cables from both the mains supply and the immersion heater, given that there's a warning that the immersion heater must be earthed?

The back box is metal if this makes any difference.

Thanks!


F

 

[westward10]

Connect them to the earth terminal in the back box.

 

[littlespark]

I’d double check the rating of the smart switch (kW)
Immersion heaters are a big load, and the electronics inside some lesser quality smart switches may not be up to the task.