Many times when you encounter this problem it is when you run your water from the tap and the room get’s a foul odor.  It can happen when you run any water, or just the hot water. 

This smelly problem can be from high levels of sulfur bacteria (Hydrogen Sulfide), or high levels of Iron bacteria. When the rotten egg smell is in the cold water – the problem is definitely worse. Iron and manganese needs to be removed and the hydrogen sulfide neutralized. Removing hardness and treating or killing bacteria will also improve the effectiveness of removing rotten egg smell. Most effective treatment is an Iron manganese filter. Can possibly be treated with specialty filters, Redox can be effective if the problem is not huge, so SSoft Redox will often be an effective treatment