Have lived in my home for over 20 yrs. We have always had well water and have always had a water softener system with a filter to help with odor and sediment. About a year ago we upgraded to a new softener system (without a filter) and it has been working wonderfully. We generally shock the well with bleach at least once a year (or when needed) and it seems to do the trick. About 2 month ago I started noticing a nasty smell, a little like rotten eggs but different that before we changed the softener out. In the past two months we have shocked the well twice. It seems to work for a while, but within a few weeks the smell came back. I was trying to find my answer online and noticed that one person mentioned that it could be the water heater. This makes some sense because we just replaced our water heater early October and it was after that when the odor started. I believe it is only in the hot water as when we take showers the odor fills the whole house. Could this order be coming from our brand new water heater? (The Anode rods do not need changed as this is again a brand new water heater.) If so how can we fix and prevent this odor from coming back? Could this have something to do with it as well?
Any advise is GREATLY Appreciated!

Thank you,
Tammy M

What type of well tank do you have, galvanized pressure tank or painted bladder tank?
If bladder tank, open a faucet and watch pressure gauge. Does pressure drop drastically and immediately? If so, when closing the faucet, does pressure go up drastically?

I believe galvanized pressure tank. It is a GE Gas Residential GG Series 40 gal water heater.

Is the well tank galvanized or painted? Does it have valve stem (like a tire) on top ?

I apologize, there is no valve stem, however I do see a pressure gauge along the pipe. I tried your water test and the gauge never moved.

Reason for my question was, if you have bladder tank (painted) and if the bladder ruptures and the water comes in contact with interior coating of the tank, that can sometimes create an odor. Of course with a galvanized tank the water is always in contact with the interior surface.

A drastic drop in pressure when a faucet is opened, is one indication of a ruptured bladder and a water logged tank, on a bladder tank.

Suggest you fill a large pot with cold water, check for odor. Cover it an heat.
Check for odor. I don't see how water heater could be creating odor. You logically would have a stronger odor when warm if there is something contaminating the water.