We have a condo in SC that we use several months a year when we are no in NY. When we get there when you turn on he faucet and showers the water smells like rotten eggs. We let the water run and then it goes away. When we are not in SC we turn off the water.

Uncirculated water that has sat for a while will have a smell, and likely discoloration, until its run awhile. Not unusual as well as drain traps losing their water seal from evaporation, and allowing sewer odors to be let back into the living spaces.

Its all good if you can clean things out after running the water for a while and it eliminates the odors and discoloration. I would still do some checking maintenance on my systems though regularly after being gone a while.

What you have is a accumulation of sulfur dioxide built up in the standing water of your pipes. By running the water you have flushed out the line. This is harmless and should be no cause for concern. Good luck, Tom​

Mrifenbu,
Electric water heaters, that sit idle for several months, can produce a rotten egg odor; it may help to turn the power off to the water heater when it is not in use for extended periods...