Why does my water softener stink?

I have worked in residential water treatment sales for over 6 years and this is a common problem. Try adding a cup of bleach to the salt tank when you add salt. This will disinfect the resin beads that are in the softener, which is important if the system has either been out of salt or not used for a long time. However, if you are smelling sulphur, most standard water softeners will not remove sulphur from the water. You may need an additional piece of equipment, such as an off-gas tank or a manganese greensand filter with potassium permanganate backwash capacity to eliminate the sulphur. Also, the odor could be coming from the hot water heater, and you may want to have it chlorinated by a plumber. Good luck!

You need to clean out the salt reserviour and add either salt or potassium, which ever your system works on then set the unit to backflush in the middle of the night when no one is using water. Often, the reserviour (ours is plastic) picks up smells from the water, sulfur and mineral smells are common.