Question
Hi Jim, and thanks for taking a moment to answer my question.

I just bought a home and it has a RainBird RC7Bi mechanical timer.  Whenever I advance the timer to an identified zone, the zone that's being irrigated changes.  It was driving me nuts!  I took apart the timer and found everything to be working correctly.  4 zones.  All have 24 VAC output.  But I noticed that the 4 output wires are only tied into 2 wires leaving the garage.  I searched and searched around the house and came across a KRain 4000 indexing valve.  How does this work?  And could that be the reason why whenever I manually advance the timer, a different zone waters?  I don't believe that there are individual solenoids.  It's almost as if the valve starts up where it left off the previous time?  Does that make sense?

Thanks,
Steve

Answer
Hey Steve, so how the indexing valve works, is basically when the water pressure is on to it, there is a mechanical turret inside, that rotates and allows water to flow through one of the outlets into the pipe. As long as the water pressure is on to it, the turret will keep rotating, allowing water to flow through one of the pipes to a section, and then it will turn to the next pipe and  allow the next section to come on, and so on and so on... What I would suggest, is that you install 4 separate automatic valves, and hook up the 4 different pipes that are discharged from the indexing valve. This way, you can control each zone differently as far as how long you want each one to run for. Some counties in Florida, have actually outlawed the indexing valves, and will give you a credit if you bring your old one in. Good luck and have a great day.