I have one of those heater element sockets which have holes in the end to take a 3/8" shaft - and I had no problems with the upper element, but the lower one is jammed up solid; with some 3/8" metal rod through the socket holes and a 4' thick-walled hollow bar on that as a breaker, it just keeps on bending the 3/8" rod where it meets the socket...
Heating around the element nut with a torch hasn't helped, nor has leaving the whole lot to soak in penetrating oil for a few hours, nor has thumping it with a big hammer to loosen the corrosion (makes me nervous, that, though - tank looks to be cast iron, and I don't want to crack it).
Worst-case I might be about to drill the darn thing out, I suppose, although I was mainly interested in checking the element for scaling, not outright replacing it (it's giving 13.8 ohms consistent with the upper one, and nothing to ground on either terminal), plus i don't want to risk trashing the tank threads.
Next attempt might be to drill the holes larger in the socket, as I have a bit of 5/8" solid rod sitting up in the workshop - but before I go modifying the tool, I was wondering if anyone had any other bright ideas? Maybe leaving it to soak overnight in penetrating oil is worth a shot?
cheers
Jules