wiring an immersion heater

oisin

I've changed a few of these in my time, but never encountered one like this. The tank is in an apartment with two seperate single immersion heaters, one for boost and one for overnight cheap rate heating. They're both 11" 3KW heaters. It's the (bottom) overnight one that's been replaced. I fitted the immersion fine but when I went to wire it I couldn't figure it out as the wiring diagram supplied bears no resemblance to the unit. The electrical supply is a three core cable.

Any I did previously I just had to connect live, neutral and earth, I'm not sure where the two white wires go. I added two pictures for clarirty, one with the thermostat in place and one without.

Any advice would be appreciated, thanks.

Bruthal

Usually when there are 2 seperate elements into a cylinder, its one for bath, one for sink, with the sink one being higher up in the cylinder. If a house has a night rate electricity meter, a single bath/sink immersion, and anything else in the house would use the night rate at night anyway.

Anyway, on to the connection question...

Remove the brown of the supply flex thats connected to the element in your photo, and connect it into one side of the blue stat. Then one white wire of the overheat stat into the other side of the stat, then the other white wire into the element end where the brown of the flex was. This means the thermostat and the overheat stat are in series.

I notice the screw is missing in the element end that the brown is currently in, it will need that to make a proper connection.

oisin

Thanks robbie7730, much appreciated. It all looks simple and logical when you have it explained to you. Thanks again.

BTW, well spotted the missing screw, I'd actually taken it out to disconnect the wiring until I got the connections sorted.

Bruthal

No bother.