Earthing

[rags116]

Probably a stupid question to most people on here but I want to fit a water tank heater timer and there is a sticker on it saying it must be earthed. there is a feed coming in with L,N and E wires and two going out to the two tanks, both with L,N and E wires.
I can connect up all the wires fine and have put the earth wires to the earth terminals in the box.
Do I need to do anything else or do I need to spur off an earth wire to something else or something (I am hoping that what I have done is enough - the earth wires just appear to be attached to the side of the plastic box (all three earth wires to the same terminal)

Any advice woudl be much appreciated. Am I already earthed or do I need to do something else?

 

[Spark123]

Connecting it to the timer earth terminal will be adequate, however I don't know about connecting two tanks to the same timer. What rating timer, what rating immersion heaters and what rating is the circuit?

 

[rags116]

Thanks for the quick reply...

By two tanks I meant two elements in the same tank. the timer is specifically designed for this as a main element and a booster element.
There are separate terminals for each in the timer.

Thanks Again!