I'm hoping some of you might be able to give me some info on an old immersion heater and how its wired. I'm going to attempt to replace an immersion heater switch that is acting up, later this evening. It's a simple ON/OFF - SINK/BATH type of switch and looks to be from the 60's-70's.
I took a quick shot of the top of the immersion heater and I was hoping to get my head around how its wired before I make an attempt at the switch.
All the wires are black and there are 4 terminals marked as follows,
The black is marked on the housing as "long element (Bath)" and goes to the L1 terminal in the bath/sink switch.
The white goes to the L2 terminal in the bath/sink swtich.
The terminals marked RED and BLUE both go to the switched side of the neutral in the switch.
I guess what I'm trying to get to the bottom of, is how this element works. It appears to me to be fed a live to the black or white (depending on sink/bath position) and the switching is on the neutral side (It appears to have some burning/arcing here on the old switch). Overall, the wiring looks very janky and hasn't been touched for years, by the looks of it.
I've tried searching online for diagrams etc and I found some info on old/wiring colours, but I haven't been able to find anything similar to this.
The heater itself is branded "Santon Otter". There are some other details on it but I forgot to take a pic. I can do so later if needed.
*Note: I took the cover off to have a peek inside in the image above. It's not actually exposed like that normally.
Any help appriciated guys.