Howard and I had a look at why the hot water is cold.
240volts gets to the heating element push-on connectors. The element should
be about 20ohms, it measures a couple of hundred ohms with a varying reading.
It appears to me that changing the element would be quite a hassle. From a two minute
look, I think it involves more disassembly than you might expect. The heating element flange is on the inside of the tank.
If you want to try it then I suggest getting the flange gasket as well as the element.
It would be a hassle if it leaked after changing the element.
Howard thinks the cost of a new heater is low enough that it’s not worth messing with it.
Note that it can’t have a water cutoff valve fitted next to it, the water has the be able to expand back up the cold pipe, see link above for the instructions.