We are trying to trace a leak and know it is between the pump outlet and a solenoid valve that operates a station. To help with knowing where to look for the leak, I need to understand how the controller works. If the master valve of the TOTAL CONTROL controller is on and all the stations are off, where is the flow of water being stopped--at each solenoid valve in the system or at the controller master valve?

We have a cistern from which we pump water for garden irrigation. The cistern and pump do not leak; we have proven this with leak tests. Water also does not leak when we turn on the pump but no one is irrigating. However, after one of the homes irrigates, water disappears slowly out of the cistern. Three of the homes are downhill from the pump and this can cause water to siphon out if the pump stops running and the station is still on.