Good day everyone
I'm a Newbie here, I've noticed that some users use the sonoff th16 with a relay/contactor. Just some advice the neutral of the sonoff in and out is one connection and not switched by the sonoff device. There's no need to use two relays or switching contacts. Just connect the neutral in of the sonoff th16 to the same connector point of the geyser neutral main supply in and neutral of the element. Only the live should run through the sonoff and relay/contactor there's no need to run the neutral through a relay or contactor.