I recently replaced the piston valve of the controller. After that, I noticed that the water softener keeps slowly draining water. Is it normal? It keeps slowly dripping through the drain line even when it is put in bypass. I don't remember the softer acted like this before. The flow indicator does not flash when there's no water usage in the house. However, I wonder if the water softener still consumes water and drains it directly? Any suggestion? Thanks a lot!