Immersion Heater Time Switch with battery backup...

[JohnW2]

The BX2000 doesn't have a clock. It just facilitates changing two supplies to one immersion - just a change-over switch.

Whoops, you're right. My mind was getting muddled with the 'Economy 7 Timers' I'd been looking at in the other TLC link that was posted It therefore makes sense!

It also allows the two supplies to two immersions - not sure what the point is in this case - just neater?

I think I understand that bit. I think the intention is that the 24/7 supply is used for the upper of two immersions (to allow 'boosts' to just heat a bit of the water) BUT (and this is the 'clever' part), per the description, if the off-peak supply (supplying the lower immersion) becomes active during a 'boost' period, it switches of the immersion using the 24/7 supply, thereby saving money.

Kind Regards, John