Running a 2kw on a 13amp socket would be just within the allowance but if running it for 10 to 12hours every night you would be
safer getting the electrics upgraded.
A 2kw heater will up the temp of 500ltrs by 50degrees in 14.5 hours with absolutely no heat escaping from the water , there's no possible way of improving on this, science fact.
I will put my immersion on tonight ( if I remember ) I will post my results tomorrow, both the starting temp at night and the temp in the morning and how long the immersion has been plugged in. I have a 3kw immersion and had an electrician upgrade my electrics in the garage. I very much doubt the results will be able to match the heat of Nathans water.
This should be interesting.
I dont belief mine is a 3kw 27inch element at all. If it is then i got a cracking deal on price as it was cheap as chips. Also my standard heavy duty oranges extension would be really warm,,,,,dangerously hot in fact.
If my tank is being filled virtually from empty from my outside ibc tank than i would run the heater for even longer as the start temp is around 16 degrees.
But by the end of the night, as shown in so many of my public videos, the water temp by 8pm is around 40 - 50 degrees. Whenni top up with the cold my starting temp is around 38 - 44 degrees. Which then dictates how long i turn the heater on for.