4 gallon electric water heater - burnt element wire

[appleimac]

Had a Ariston GL4 electric hot water heater supplementing the hot water in my condo for over ten years - just had to clean out every 6 months and replace anode rod.  Finally had to replace it, believe was because a burnt appearance on left connection to electric element.  Replaced it with the new replacement, the Bosch equivalent.  Turned up the temp for dishwasher, then back down when done. Started smelling a burning smell when water heater turned on.  Finally pulled the faceplace after smell stronger after several uses, found left electrical connection to water heater element totally burnt and black, steel on heating element base that shows without pulling element out - appears brown instead of steel looking, and maybe some greenishness. Bosch said to try to test element, and they will send out new thermostat and element - why would this happen? After cleaning tank out, I have put a bit of vinegar into the tank and flushed it out -I assume that wouldn't do it.  The water heater is plugged into a GFI outlet, which I pushed the test button to ensure it is working.   I have bought a heavy duty outlet strip (not a surge protector) - from TrippLIte, with its own 15 amp breaker - and the Tripp Lite OSI block or whatever surge protector, which they claim is the only product they make heavy duty enough for the water heater, which will plug into the heavy duty strip - any thoughts? The strip is necessary to be able to properly use the surge protector -

[johntech]

A loose connector can generate heat and burn terminals. I would replace the terminal that connects to that side of the element.