It seems to me some frost damage has been done?
The only cause can be the electric heating element, my guess is there is a leak from the tank in the centre where the tie rod holds the tank tight to the heat exchanger, water from here is then getting onto the elements electrical connections.
If you grab the tank in this area and try and rock it side to side, it should be solid onto the heat exchanger that is set in the wall, therefore unable to move, I would expect the water freezing has expanded and pushed the tank backwards, this will allow some movement which means the tank is distorted and leaking.
Good news I suppose is it can be repaired, if very minor you may be able to *** the nut tight to reseal it but more likely I'm sorry to say, it's worse?!
Facebook
Twitter