Installing Economy 7 immersion heater controller

[It's not Rocket Science..]

Having replaced my hot water tank, I am now sorting out some of the dodgier aspects of the previous owners wiring and installing a dedicated economy 7 controller for my immersion heater.

My understanding is that I need to have a twin pole isolating switch inline between the immersion and live feed. Not a problem. my only question is does it matter which side of the economy 7 controller it goes? i.e do I put it on the mains feed side, or the element load side of the circuit.

Thanks

Matt

 

[Lectrician]

Load side, and leave the DP isolator switched on.

Better still, why have you not fitted dual immersion elements as you renewed the tank?