Question
Jim,
Just recently bought a house and the prev owner demonstrated the sprinkler system and it worked fine.  It has been off for the winter.  Trying to get system on and no luck.  Verified good water supply at all valves by manually working solenoids.  Have a Rainbird RC7BI controller and have verified 26.4v output and same at all solenoids.  I can't imagine all the solenoids going bad over the winter.  I am baffled.  What is my next step?
Greg

Answer
Hey Greg, just so I am clear on everything. First when you turn the solenoid on manually, the valve opens up and the heads work good. Second you checked the voltage at the solenoids, and they are receiving 26 volts. I would first have someone check one of your solenoids, or replace just one solenoid and see if it makes a difference. I doubt all the solenoids could go bad at once. However,it could be if the system froze, the diaphrams might have been damaged. After confirming if the solenoids are good, and the valves still don't operate. I would suggest replacing one of the diaphrams and see if this doesn't do the trick. Sometimes you can turn the valve on manually and they will work fine even if the diaphrams are going bad, but hey won't operate by the controller. Good luck and have a great day.