Hi, I'm planning out a major house extension and thinking about how I control the electric hot water cylinder. I'd like to have it set to heat overnight, with an automatic afternoon boost if the temperature gets below a certain point. I have a peak/off-peak/night power tariff so afternoon power is cheap, but not as cheap as night power. I'd probably have a temperature threshold of 65-70C overnight (set on the elements thermostat) then perhaps 50C for the afternoon boost threshold (set on controller). Will have a tempering valve set at or below 50C so temperature at tap would remain constant.

I'm not super familiar with how water cylinders - does anyone know how I could add a temperature probe? Are there thermowells in the elements? I'd be looking at a pretty basic cylinder so wouldn't have all the extra threaded openings found on solar/wetback cylinders. Worst case would be strapping the probe on the outlet nipple, but I'd imagine the temperature would fluctuate depending on whether hot water is being drawn or not.

Thanks