Solahart solar geyser temperature

[aomar296]

Hi all

Is there a relatively quick and easy device that I can install that will help tell me the temperature of the water in my solar geyser?

I know about geyserwise but I don't need the timer. I literally just need to know how hot the water is and if I need to turn on my element.

Thanks

 

[Tradezzz]

Have the same question..
This would really help with optimizing geyser usage. Preferably something thay can integrate into Home Assistant.